diff --git a/docs/openup/model/BUILD-CHECKLIST.md b/docs/openup/model/BUILD-CHECKLIST.md
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+# Skara Brae — EA Model Build Checklist (WI-2)
+
+Version 1.0 (2026-10-03) · Prepared by COD per `design-wi-2-architecture-cleanup.md` §11.b.4.
+Sources (authoritative, do not deviate): `docs/openup/requirements/use-case-model.md`,
+`docs/openup/analysis-design/uc-realization-mapping.md` (§1 tree, §2 realization table),
+`docs/openup/requirements/supplementary-specifications.md`, design note §3 (boundary rules).
+Drift rule: markdown and model must agree; a mismatch is a defect fixed in the same cycle.
+
+This checklist is written to be clicked through in EA **or** executed via
+`scripts/openup/build-model.ps1` (then verified below). The per-discipline element lists
+are complete: nothing outside them belongs in the WI-2 model.
+
+---
+
+## 0. Prerequisites (Windows machine — see model/README.md for why not Linux)
+
+1. skara-brae-common checked out (branch `wi-2-openup-docs` or later).
+2. EA installed and licensed. Copy the EA installation's empty-model template to the
+   model home:
+   `C:\Program Files\Sparx Systems\EA\EABase.eapx` → `docs/openup/model/skara-brae.eapx`
+   (exact install path may differ; the file is the standard empty `.eapx` template.
+   Do **not** derive the skeleton from keyfob-station's model — it carries keyfob content).
+3. PowerShell 5.1+ (built into Windows) for the script path.
+
+## 1. Model root
+
+- Rename the default model root to **`Skara Brae`** (keyfob equivalent: single model root).
+
+---
+
+## 2. Requirements discipline
+
+### 2.1 Package `Requirements`
+
+Create package **`Requirements`** directly under the model root.
+
+### 2.2 Package `Requirements / Vision`
+
+- Notes: purpose statement source = `docs/openup/requirements/vision.md` (the markdown is
+  the human-facing source; the model carries the product purpose in the package notes and
+  links, not a full copy).
+
+### 2.3 Package `Requirements / Use Case Model`
+
+**Actors (exactly 3)** — type `Actor`, notes verbatim from the Actors table:
+
+| Actor | Notes |
+|---|---|
+| `Player` | Authenticated user owning one or more characters (JWT role `player`). |
+| `Administrator` | Player with elevated rights (`role = admin`); may view any user's and any character's resources read-only. |
+| `Guest` | Unauthenticated caller; only register/login are open. |
+
+**Use cases (exactly 12)** — type `UseCase`, names verbatim:
+
+`UC-01 Register Account`, `UC-02 Authenticate`, `UC-03 Manage Characters`,
+`UC-04 Browse Game Catalogue`, `UC-05 Train Stat`, `UC-06 Manage Equipment`,
+`UC-07 Trade at Shop`, `UC-08 Run Adventure`, `UC-09 Heal at Temple`,
+`UC-10 Practice Bard Song`, `UC-11 Study Magic`, `UC-12 Level Up at Review Board`.
+
+Element notes: the UC's precondition line(s) verbatim from `use-case-model.md`; plus:
+- UC-05 note appends: *includes Regenerate Resources.*
+- UC-08 note appends: *includes Regenerate Resources, Resolve Combat. Exception: encounter
+  references an unknown enemy → 500 (post WI-2; previously a panic). WI-2 design driver
+  (`sb_core::adventure` extraction).*
+- Include targets are **sub-flows, not use case elements** (only 12 UCs exist) — model the
+  includes in the notes, **not** as `«include»` connectors.
+
+**Associations (exactly 13)** — type `Association`, Actor → UseCase:
+
+| Actor | Use cases |
+|---|---|
+| `Guest` | UC-01, UC-02 |
+| `Player` | UC-03, UC-04, UC-05, UC-06, UC-07, UC-08, UC-09, UC-10, UC-11, UC-12 |
+| `Administrator` | UC-03 (read-only) |
+
+**Scenarios** — stored on each use case (`Scenarios` collection), types are EA's
+`Basic Path` / `Alternate` / `Exception`. Naming and structuring rules used below
+(also implemented in `build-model.ps1`):
+- Markdown "Main success scenario" → scenario **Main Success Scenario** (`Basic Path`);
+  its numbered list items become ordered **steps**, each step's **Actor** = the leading
+  grammatical subject of the step text (`Player`/`Guest` → that actor; otherwise `System`).
+- Markdown "**Scenario (x):**" block → scenario named **x** (`Alternate`); prose text goes
+  into the scenario notes verbatim.
+- Markdown "**Alternate flows:**" prose → one scenario **Alternate flows** (`Alternate`),
+  prose verbatim in notes.
+- Markdown "**Exception:**" prose → scenario **Exception** (`Exception`), prose verbatim.
+- Precondition text rides on the scenario notes of the Main Success Scenario.
+- UC-11 has no labeled main scenario in the markdown; its first listed scenario
+  (view spellbook) serves as the Basic Path, the remaining "Scenario (x)" blocks as
+  `Alternate`.
+- Parenthetical actor remarks on a step text (e.g. UC-03 step 1 "(Admin may act for any
+  user)") move to the scenario notes to keep the step actionable; the wording is kept.
+
+| UC | Scenario (type) | Steps (Actor: text) / Notes |
+|---|---|---|
+| UC-01 | Main Success Scenario (Basic Path) | Guest: Guest submits name (3–32 chars) and password (≥ 6 chars). · System: System verifies the name is unused → 409 CONFLICT if taken. · System: System hashes the password (argon2), assigns the `player` role and the next id, persists the user. · System: System issues a JWT (HS256, `player` role) and returns `{token, user_id, name, role}`. |
+| UC-01 | Alternate flows (Alternate) | Notes: name length invalid → 400; password too short → 400; name taken → 409; hashing/token failure → 500. |
+| UC-02 | Main Success Scenario (Basic Path) | Guest: Guest submits name and password. · System: System finds the user (401 if unknown) and verifies the password hash (401 on mismatch). · System: System issues a JWT carrying the user's real role (`admin`/`player`) and returns `{token, user_id, name, role}`. |
+| UC-02 | Alternate flows (Alternate) | Notes: unknown name or wrong password → 401 UNAUTHORIZED; token creation failure → 500. |
+| UC-03 | Main Success Scenario (create) (Basic Path) | Notes: Admin may act for any user. · Player: Player submits character name, race, class for their user id. · System: System validates the target user exists (404) and the trimmed name is 1–32 chars (400). · System: System rolls stats (d6+5 base 6–16 per stat ± race modifiers), computes max HP/energy/nerve from class, grants starting gold (50) and level-1 class spells to casters. · System: System assigns the next character id, stores and persists the character; returns it fully. |
+| UC-03 | list/view (Alternate) | Notes: Player lists their characters (Admin: any user's); the system applies Regenerate Resources to each returned character and returns them. Viewing one character applies regen then returns it. |
+| UC-03 | Alternate flows (Alternate) | Notes: foreign user/character without admin role → 403 FORBIDDEN; user/character not found → 404; invalid name → 400. |
+| UC-04 | Main Success Scenario (Basic Path) | Player: Player requests the catalogue: races, classes, items (optional type/quality/slot filters), enemies, or adventure zones. · System: System returns static game data loaded from `skara-brae-common` JSON (class info is enriched with `is_caster`). |
+| UC-04 | Alternate flows (Alternate) | Notes: single item by unknown id → 404; filters may return an empty list (not an error). |
+| UC-05 | Main Success Scenario (Basic Path) | Notes: Precondition: character exists and caller may act on it. · Player: Player selects a training ground (strength / dexterity / constitution / intelligence / luck) and submits the stat name. · System: System applies Regenerate Resources. · System: System checks energy ≥ 1 and gold ≥ training cost (cost grows ~1.3× per 10 stat points). · System: System deducts 1 energy and the gold cost, increments the stat; constitution training recomputes max HP (current HP clamped). · System: System persists and returns `{success, message, character}`. |
+| UC-05 | Alternate flows (Alternate) | Notes: foreign character → 403; character not found → 404; not enough energy → 422; not enough gold → 422; unknown stat name → 400. |
+| UC-06 | Main Success Scenario (equip) (Basic Path) | Player: Player submits an item id from their inventory. · System: System moves the item from inventory to its slot; a previously equipped item in that slot returns to inventory. · System: System persists and returns the updated character. |
+| UC-06 | unequip (Alternate) | Notes: Player submits a slot name; the system moves the equipped item back to inventory. |
+| UC-06 | Alternate flows (Alternate) | Notes: foreign character → 403; character/item not found → 404; item not in inventory → 400; nothing equipped in slot → 400. |
+| UC-07 | Main Success Scenario (buy) (Basic Path) | Player: Player views the shop: always-stocked items plus rotating stock (with quantities) alongside their inventory. · Player: Player submits `buy` + item id. · System: System checks gold ≥ price (422), and for non-always-in-stock items decrements the limited stock (410 GONE if 0). · System: System deducts gold, adds the item to inventory, persists character and stock; returns `{success, message, gold}`. |
+| UC-07 | sell (Alternate) | Notes: Player submits `sell` + item id; system removes the first matching inventory item, pays half the item value, increments shop stock for non-permanent items. |
+| UC-07 | Alternate flows (Alternate) | Notes: unknown action or item not owned (sell) → 400; item not found → 404; insufficient gold → 422; stock exhausted → 410. |
+| UC-08 | Main Success Scenario (Basic Path) | Notes: Precondition: character exists and caller may act on it. · Player: Player requests an adventure for a zone (default `skara_brae_streets`). · System: System validates the zone (404) and applies Regenerate Resources. · System: System refuses incapacitated characters (HP ≤ 0 → 400) and characters with nerve below the zone cost (422); otherwise deducts the nerve cost. · System: System draws one enemy from the zone's weighted encounter table. · System: System resolves turn-based combat: open-ended d100 attack rolls, OB vs DB, RoleMaster crit tables with level-gap damage caps, active bard song effects, active spell damage/heal per round. · System: On player victory: XP and gold per the enemy definition, character HP set to the last round's defender HP, and loot dropped per-item chance rolls (only items existing in the catalogue). · System: On defeat: character HP set to 0; no rewards. · System: Spell-point upkeep is charged whenever a spell was active, win or lose. · System: System persists the character and returns `{zone, enemy, combat_log, loot}` (loot = item display names). |
+| UC-08 | Alternate flows (Alternate) | Notes: foreign character → 403; character/zone not found → 404; incapacitated → 400; insufficient nerve → 422. |
+| UC-08 | Exception (Exception) | Notes: encounter references an unknown enemy (data error) → 500 (post WI-2; previously a panic). |
+| UC-09 | Main Success Scenario (Basic Path) | Player: Player requests healing, optionally `partial`. · System: System computes missing HP; full heals all, partial heals half (rounded up); cost = amount healed, minimum 1 gold. · System: System checks gold (422), deducts it, restores HP, persists; returns `{hp, max_hp, gold, healed: true}`. |
+| UC-09 | Alternate flows (Alternate) | Notes: foreign character → 403; not found → 404; already at full HP → 400; insufficient gold → 422. |
+| UC-10 | Main Success Scenario (Basic Path) | Notes: Precondition: character class is Bard. · Player: Player views available songs (level-gated, with combat effect descriptions) and the active song. · Player: Player submits a song id; system validates level requirement (422) and sets it active; returns `{success, message, active_song}`. |
+| UC-10 | clear (Alternate) | Notes: submitting no song id clears the active song. |
+| UC-10 | Alternate flows (Alternate) | Notes: non-Bard → 403; unknown song → 404; level too low → 422; foreign character → 403; not found → 404. |
+| UC-11 | Main Success Scenario (view spellbook) (Basic Path) | Notes: Precondition: character belongs to a caster class (Mage→magician, Wizard, Conjurer, Sorcerer). Spell level = (character level / 3) + 1 — uncapped by code (level 100 → spell level 34); learn requests are validated to 1–7. · Player: Player requests their spellbook: caster class, current spell level, spell points, spells up to the achievable level (each marked known), and the learn-cost table for levels 2–7. |
+| UC-11 | learn spell level (Alternate) | Player: Player submits a spell level (1–7). · System: System validates caster class (403), level range (400), level not above the character's current spell level (422), gold ≥ learn cost (422), and that new spells exist (400). · System: System deducts gold, adds all unknown spell ids of that level, recomputes and refills max spell points; returns `{learned_count, spell_points, max_spell_points, gold}`. |
+| UC-11 | activate/clear active spell (Alternate) | Player: Player submits a spell id (or empty to clear). · System: System validates the spell is known (403), exists (404), and spell points suffice (422); deducts the spell's points and sets it active; returns `{active_spell, spell_points}`. |
+| UC-12 | Main Success Scenario (Basic Path) | Player: Player requests a level-up. · System: System validates: below max level 100, XP ≥ 18·100·(level)² for the next level (i.e. `xp_for_level(next)`), gold ≥ 500·next level. · System: System deducts the gold cost, increments the level, recomputes and fully restores HP/energy/nerve and max spell points; persists; returns `{success, message, character}`. |
+| UC-12 | Alternate flows (Alternate) | Notes: all of already at max level; not enough XP; not enough gold → 422. Foreign character → 403; not found → 404. |
+
+**Diagram** `Skara Brae Use Case Overview` (type `UseCase`): place all 3 actors (left
+column) and all 12 use cases (right grid).
+
+### 2.4 Package `Requirements / Supplementary Specifications`
+
+- One child element per top-level section of `requirements/supplementary-specifications.md`,
+  type `Requirement`, name = `SS-<n> <section title>` with the section's content in notes:
+  `1. Performance / Scalability`, `2. Reliability / Correctness`,
+  `3. Quality Gates (per-commit acceptance)`, `4. Data`, `5. Security`,
+  `6. Constraints`, `7. Usability / API`.
+- `Trace` connectors from each `SS-n` element to the use cases the section names
+  (the spec text cites the UCs; when it names none, leave untraced rather than guessing).
+
+---
+
+## 3. Analysis-Design discipline
+
+### 3.1 Package `Analysis-Design`
+
+Create package **`Analysis-Design`** under the model root (mapping §1 name — note:
+keyfob uses `Analysis & Design`; here the mapping document says `Analysis-Design` —
+follow the mapping).
+
+### 3.2 Package `Analysis-Design / Architecture Overview`
+
+- Notes: the dependency rule verbatim from `uc-realization-mapping.md` §2
+  ("all controllers/entities above live in `sb-core`/`sb-shared` …; the single current
+  violations (ShopService, HealingService, parts of MagicService in sb-api) are recorded
+  as debt … stale docs are defects") + design note §3 boundary rules.
+- Three cross-cutting elements (type `Class`, notes from the mapping's cross-cutting
+  paragraph):
+  1. `DomainError` — notes: `sb-core::error::DomainError` + `sb-api::routes::domain_status`
+     (status mapping table, design note §4.1) realize the error paths of UC-05/06/08/12.
+  2. `Constants` — notes: `sb-core::constants` realizes NFR "no magic numbers".
+  3. `Responses` — notes: `sb-api::routes::responses` realizes NFR-19 (wire-format freeze).
+
+### 3.3 Twelve realization packages
+
+For **each** entry in `docs/openup/model/exports/uc-realizations.json`
+(generated from mapping §2 — 12 packages, 36 elements):
+
+1. Package `UC-<NN> Realization` under `Analysis-Design`.
+2. Inside it, one `Collaboration` element named like the package, with a `Realization`
+   connector (Collaboration → the use case element in `Requirements / Use Case Model`).
+3. Inside it, one `Class` element per mapping row:
+   - Name = analysis class (e.g. `AdventureService`).
+   - Stereotype = `controller` / `entity` / `boundary` (mapping §2 column).
+   - Notes = the mapping's *Design element* cell verbatim, plus the *Notes* cell
+     (e.g. `` `sb-core::adventure::run_adventure` (**new, WI-2**) + `services::pick_enemy`
+     → `Result` (WI-2) — takes injected rng; `DomainError` (WI-2)``).
+4. One class diagram per realization package (name = package name), all its classes placed.
+
+Element counts for verification: UC-01:3, UC-02:2, UC-03:4, UC-04:2, UC-05:3, UC-06:3,
+UC-07:3, UC-08:5, UC-09:2, UC-10:3, UC-11:3, UC-12:3 — total 36.
+
+---
+
+## 4. Verification (design §11.d)
+
+1. Model opens clean (no missing-package errors).
+2. `Requirements → Use Case Model` shows exactly 3 actors + 12 use cases; every UC carries
+   its Main Success Scenario plus the alternates/exceptions from the table above, with
+   per-step actors.
+3. Spot-check two scenarios against `requirements/use-case-model.md` (recommended: UC-08
+   MSS — 9 steps, and UC-11 learn spell level — 3 steps).
+4. 12 `UC-N Realization` packages exist under `Analysis-Design` with the element counts
+   above; spot-check the UC-08 realization table against `uc-realization-mapping.md` §2.
+5. Association count is 13; there are no `«include»` connectors (includes live in UC notes).
+
+## 5. Export + commit (design §11.d.4–5)
+
+1. Run `scripts/openup/export-model.ps1` → regenerates
+   `docs/openup/model/exports/use-case-model.json`, `uc-realizations.json` and an XMI
+   backup; confirm the diff is expected (`uc-realizations.json` must be unchanged in
+   content — it was generated from the mapping markdown).
+2. Save the model; commit `.eapx` + `exports/` + `scripts/openup/` together as one commit
+   `openup: EA model WI-2 baseline` in **skara-brae-common**.
diff --git a/docs/openup/model/README.md b/docs/openup/model/README.md
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+# docs/openup/model/ — EA Model Home (WI-2 status)
+
+Per `design-wi-2-architecture-cleanup.md` §11 (decision reversal 2026-10-03): the binary
+EA model lives here at `skara-brae.eapx` with generated exports under `exports/`; generator
+scripts live in `scripts/openup/` (repo root). Markdown stays the content source of truth;
+exports are generated, never hand-edited.
+
+## Status after COD session 2 (2026-10-03, Linux agent)
+
+| Design item (§11.b/c) | Status |
+|---|---|
+| §11.b.1 clone keyfob-station read-only | done — studied `add-wi19-uc11.ps1` (scenario embedding: `Name/Type/Notes/Steps` arrays with per-step `Actor`) and `export-model-json.ps1` (COM walk → JSON); patterns reused in the scripts below |
+| §11.b.3 `.eapx` skeleton from EA's `EABase.eapx` | **not done — platform gap.** No `EABase.eapx` exists on this Linux machine (searched `~`, `~/.wine`, `/mnt`, `/media`, `/opt`, `/usr/local`); EA is a Win32 application. The binary is deliberately NOT committed and NOT derived from keyfob's model (it carries keyfob content). Copy it during the Windows session (see BUILD-CHECKLIST §0). |
+| §11.b.4 build checklist | done — `BUILD-CHECKLIST.md` (packages, actors, use cases, scenarios, associations, realization packages — complete and clickable) |
+| §11.c `build-model.ps1` / `export-model.ps1` | committed, adapted from the keyfob patterns; **Windows-gated** — this machine has no EA COM automation (and no `pwsh`), so they could not be executed here. They are prepared, not proven. |
+| §11.c machine-readable intermediates | `exports/uc-realizations.json` generated (by `scripts/openup/markdown-to-json.py`, tested locally) from mapping §2 — 12 realizations, 36 elements. `exports/use-case-model.json` is **not** generated here: the markdown carries no per-step actor tags, so a faithful JSON intermediate cannot be produced mechanically. Per §11.c's recorded fallback, `build-model.ps1` embeds the scenario content as PowerShell arrays (keyfob pattern); the human gate verifies it against `use-case-model.md` via the checklist. |
+
+## Linux constraint and the two options
+
+The EA pipeline is PowerShell + COM automation (`New-Object -ComObject EA.App`) against a
+`.eapx` (MS Access/Jet) file — Windows-only. This session ran on Linux. Options:
+
+1. **Run the pipeline on the Windows/EA machine (planned path).** `BUILD-CHECKLIST.md`
+   §0–§5 is the session script: copy `EABase.eapx` → `skara-brae.eapx`, run
+   `build-model.ps1`, verify per checklist §4, run `export-model.ps1`, commit
+   `.eapx` + `exports/` + `scripts/openup/` as `openup: EA model WI-2 baseline`.
+2. **EA manual XML export → agent-side transform.** If the COM scripts hit friction in EA,
+   export the package manually from the EA UI (`Publish → XML / XMI`), drop the file into
+   `exports/`, and the agent side can transform/validate it into the JSON intermediates
+   with a small local script (same role as `markdown-to-json.py`). The committed scripts
+   remain the reproducible path of record.
+
+## Drift rule
+
+Markdown (`use-case-model.md`, `uc-realization-mapping.md`) and the model must agree;
+exports are generated; a mismatch is a defect fixed in the same cycle (stale docs are
+defects). The human gate (design §11.d) owns `.eapx` editing/verification — never the agent.
diff --git a/docs/openup/model/exports/uc-realizations.json b/docs/openup/model/exports/uc-realizations.json
new file mode 100644
index 0000000..2fef88f
--- /dev/null
+++ b/docs/openup/model/exports/uc-realizations.json
@@ -0,0 +1,295 @@
+{
+  "exportedFrom": "docs/openup/analysis-design/uc-realization-mapping.md §2, generated by scripts/openup/markdown-to-json.py — generated file, never hand-edit",
+  "realizations": [
+    {
+      "id": "UC-01 Realization",
+      "elements": [
+        {
+          "name": "AccountRegistry",
+          "stereotype": "controller",
+          "designElement": "`sb-api::routes::{register, seed_users}`",
+          "notes": "argon2 hash via `sb-auth::hash`; JWT via `sb-auth::jwt`"
+        },
+        {
+          "name": "UserAccount",
+          "stereotype": "entity",
+          "designElement": "`sb-shared::user::User`, `Role`",
+          "notes": "persisted via `sb-db::Database`"
+        },
+        {
+          "name": "AuthBoundary",
+          "stereotype": "boundary",
+          "designElement": "`POST /api/auth/register`, `AuthResponse`",
+          "notes": ""
+        }
+      ],
+      "useCase": "Register Account"
+    },
+    {
+      "id": "UC-02 Realization",
+      "elements": [
+        {
+          "name": "Authenticator",
+          "stereotype": "controller",
+          "designElement": "`sb-api::routes::login`, `sb-auth::{hash::verify_password, jwt::create_token}`",
+          "notes": ""
+        },
+        {
+          "name": "TokenService",
+          "stereotype": "boundary",
+          "designElement": "`POST /api/auth/login`, `AuthResponse`, `middleware::auth::auth_middleware`",
+          "notes": "middleware guards all UC-03…12"
+        }
+      ],
+      "useCase": "Authenticate"
+    },
+    {
+      "id": "UC-03 Realization",
+      "elements": [
+        {
+          "name": "CharacterFactory",
+          "stereotype": "controller",
+          "designElement": "`sb-core::character::create_character`",
+          "notes": "takes injected rng (WI-1)"
+        },
+        {
+          "name": "Character",
+          "stereotype": "entity",
+          "designElement": "`sb-shared::character::Character` (+ `Race`, `Class`, `CharacterStats`)",
+          "notes": ""
+        },
+        {
+          "name": "CharacterCatalog",
+          "stereotype": "boundary",
+          "designElement": "`GET/POST /api/users/{id}/characters`, `GET /api/characters/{id}`",
+          "notes": "store: `AppState.characters`"
+        },
+        {
+          "name": "ResourceRegenerator",
+          "stereotype": "entity",
+          "designElement": "`sb-core::character::apply_regen` (+ regen constants — WI-2 names them)",
+          "notes": "included sub-flow"
+        }
+      ],
+      "useCase": "Manage Characters"
+    },
+    {
+      "id": "UC-04 Realization",
+      "elements": [
+        {
+          "name": "CatalogueBrowser",
+          "stereotype": "boundary",
+          "designElement": "`GET /api/{races,classes,items,enemies,adventures}`; response types `sb-shared::responses`",
+          "notes": "data from `sb-common` JSON via `sb-core::{character::RACES/CLASSES, data, items}`"
+        },
+        {
+          "name": "GameData",
+          "stereotype": "entity",
+          "designElement": "`sb-core::data::{EnemyDef, ZoneDef, EncounterEntry, LootDrop}`, `items::load_all_items`",
+          "notes": ""
+        }
+      ],
+      "useCase": "Browse Game Catalogue"
+    },
+    {
+      "id": "UC-05 Realization",
+      "elements": [
+        {
+          "name": "TrainingService",
+          "stereotype": "controller",
+          "designElement": "`sb-core::services::train_stat`",
+          "notes": "error type `DomainError` (WI-2)"
+        },
+        {
+          "name": "TrainingGrounds",
+          "stereotype": "entity",
+          "designElement": "`sb-core::character::TRAINING_GROUNDS`, `training_cost` (+ cost constants WI-2)",
+          "notes": ""
+        },
+        {
+          "name": "GymBoundary",
+          "stereotype": "boundary",
+          "designElement": "`GET/POST /api/characters/{id}/gym`, `GymResponse`, `TrainStatResponse`",
+          "notes": ""
+        }
+      ],
+      "useCase": "Train Stat"
+    },
+    {
+      "id": "UC-06 Realization",
+      "elements": [
+        {
+          "name": "EquipmentService",
+          "stereotype": "controller",
+          "designElement": "`sb-core::services::{equip_item, unequip_item}`",
+          "notes": "`DomainError` (WI-2)"
+        },
+        {
+          "name": "Equipment/Inventory",
+          "stereotype": "entity",
+          "designElement": "`Character.equipment` / `.inventory`, `sb-shared::item::Item`",
+          "notes": ""
+        },
+        {
+          "name": "EquipmentBoundary",
+          "stereotype": "boundary",
+          "designElement": "`POST /api/characters/{id}/{equip,unequip}`",
+          "notes": ""
+        }
+      ],
+      "useCase": "Manage Equipment"
+    },
+    {
+      "id": "UC-07 Realization",
+      "elements": [
+        {
+          "name": "ShopService",
+          "stereotype": "controller",
+          "designElement": "`sb-api::routes::{shop_action, buy_item, sell_item}` (handler-side; extraction candidate, design note Q3)",
+          "notes": "prices: `sb-core::items::{item_price, item_sell_price}`"
+        },
+        {
+          "name": "ShopStock",
+          "stereotype": "entity",
+          "designElement": "`AppState.shop_stock`",
+          "notes": "persisted via `sb-db`"
+        },
+        {
+          "name": "ShopBoundary",
+          "stereotype": "boundary",
+          "designElement": "`GET/POST /api/characters/{id}/shop`, `ShopResponse`, `ShopActionResponse`",
+          "notes": ""
+        }
+      ],
+      "useCase": "Trade at Shop"
+    },
+    {
+      "id": "UC-08 Realization",
+      "elements": [
+        {
+          "name": "AdventureService",
+          "stereotype": "controller",
+          "designElement": "`sb-core::adventure::run_adventure` (**new, WI-2**) + `services::pick_enemy` → `Result` (WI-2)",
+          "notes": "takes injected rng; `DomainError` (WI-2)"
+        },
+        {
+          "name": "CombatEngine",
+          "stereotype": "entity",
+          "designElement": "`sb-core::combat::{resolve_combat_full, resolve_attack, crit tables, open_ended_roll}` + combat constants (WI-2)",
+          "notes": ""
+        },
+        {
+          "name": "Combatant",
+          "stereotype": "entity",
+          "designElement": "`sb-core::combat::CombatStats`",
+          "notes": "built from Character/EnemyDef"
+        },
+        {
+          "name": "SpellEffect / BardSong",
+          "stereotype": "entity",
+          "designElement": "`sb-core::combat::SpellEffect`, `sb-core::spells`, `sb-core::songs`",
+          "notes": ""
+        },
+        {
+          "name": "AdventureBoundary",
+          "stereotype": "boundary",
+          "designElement": "`GET /api/characters/{id}/adventure`; `AdventureRunResponse` (**new, WI-2**), `sb-shared::responses::CombatLog`",
+          "notes": ""
+        }
+      ],
+      "useCase": "Run Adventure"
+    },
+    {
+      "id": "UC-09 Realization",
+      "elements": [
+        {
+          "name": "HealingService",
+          "stereotype": "controller",
+          "designElement": "`sb-api::routes::heal_character` (handler-side; extraction candidate, Q3)",
+          "notes": ""
+        },
+        {
+          "name": "TempleBoundary",
+          "stereotype": "boundary",
+          "designElement": "`POST /api/characters/{id}/heal`; `HealResponse` (**new, WI-2**)",
+          "notes": ""
+        }
+      ],
+      "useCase": "Heal at Temple"
+    },
+    {
+      "id": "UC-10 Realization",
+      "elements": [
+        {
+          "name": "SongService",
+          "stereotype": "controller",
+          "designElement": "`sb-api::routes::set_song`; `sb-core::songs::available_songs`",
+          "notes": ""
+        },
+        {
+          "name": "BardSong",
+          "stereotype": "entity",
+          "designElement": "`sb-core::songs::BARD_SONGS`, `Character.active_song`",
+          "notes": ""
+        },
+        {
+          "name": "SongBoundary",
+          "stereotype": "boundary",
+          "designElement": "`GET/POST /api/characters/{id}/songs`, `SongsResponse`, `SetSongResponse`",
+          "notes": ""
+        }
+      ],
+      "useCase": "Practice Bard Song"
+    },
+    {
+      "id": "UC-11 Realization",
+      "elements": [
+        {
+          "name": "MagicService",
+          "stereotype": "controller",
+          "designElement": "`sb-api::routes::{get_spells, learn_spell_level}`; `sb-core::spells::{spells_for_class, spell_learn_cost, max_spell_points, caster_spell_level (WI-2)}`",
+          "notes": ""
+        },
+        {
+          "name": "Spell",
+          "stereotype": "entity",
+          "designElement": "`sb-core::spells::SpellDef`, `Character.{known_spells, active_spell, spell_points}`",
+          "notes": ""
+        },
+        {
+          "name": "MagicBoundary",
+          "stereotype": "boundary",
+          "designElement": "`GET/POST /api/characters/{id}/spells`; `SpellbookResponse`, `LearnSpellResponse` (**new, WI-2**)",
+          "notes": ""
+        }
+      ],
+      "useCase": "Study Magic"
+    },
+    {
+      "id": "UC-12 Realization",
+      "elements": [
+        {
+          "name": "ReviewBoard",
+          "stereotype": "controller",
+          "designElement": "`sb-core::character::level_up`",
+          "notes": "`DomainError` (WI-2)"
+        },
+        {
+          "name": "Progression",
+          "stereotype": "entity",
+          "designElement": "`sb-core::character::{xp_for_level, level_up_cost, MAX_LEVEL}` (+ curve constants WI-2)",
+          "notes": ""
+        },
+        {
+          "name": "ReviewBoundary",
+          "stereotype": "boundary",
+          "designElement": "`POST /api/characters/{id}/level-up`, `LevelUpResponse`",
+          "notes": ""
+        }
+      ],
+      "useCase": "Level Up at Review Board"
+    }
+  ],
+  "crossCutting": "Cross-cutting design elements (WI-2): `sb-core::error::DomainError` + `sb-api::routes::domain_status` (status mapping table, design note §4.1) realize the error paths of UC-05/06/08/12; `sb-core::constants` realizes NFR \"no magic numbers\"; `sb-api::routes::responses` realizes NFR-19 (wire-format freeze).",
+  "dependencyRule": "Dependency rule check (Clean Architecture): all controllers/entities above live in `sb-core`/`sb-shared` (domain side, no HTTP imports); all boundaries live in `sb-api`; the single current violations (ShopService, HealingService, parts of MagicService in sb-api) are recorded as debt with a follow-up question — the model must not paper over them (stale docs are defects)."
+}
diff --git a/scripts/openup/build-model.ps1 b/scripts/openup/build-model.ps1
new file mode 100644
index 0000000..e3b09bf
--- /dev/null
+++ b/scripts/openup/build-model.ps1
@@ -0,0 +1,456 @@
+# Skara Brae — EA model builder (WI-2), adapted from keyfob-station's
+# generate-usecase-model.ps1 / add-wi19-uc11.ps1 patterns (COM automation).
+#
+# Design: skara-brae-common docs/openup/analysis-design/design-wi-2-architecture-cleanup.md §11.
+# Content sources (authoritative): docs/openup/requirements/use-case-model.md,
+# docs/openup/analysis-design/uc-realization-mapping.md, docs/openup/model/BUILD-CHECKLIST.md.
+#
+# Platform: Windows + installed EA. The .eapx skeleton must exist first — copy the EA
+# installation's EABase.eapx to docs/openup/model/skara-brae.eapx (see model/README.md;
+# never derive it from keyfob-station's model).
+#
+# Scenario content is embedded below as arrays (keyfob fallback pattern, §11.c) because
+# the markdown does not carry machine-readable per-step actor tags; the human gate
+# verifies it against use-case-model.md via BUILD-CHECKLIST.md §4.
+# Realization packages are built from the generated intermediate
+# docs/openup/model/exports/uc-realizations.json (scripts/openup/markdown-to-json.py).
+
+$ErrorActionPreference = 'Stop'
+
+$repoRoot  = (Resolve-Path (Join-Path $PSScriptRoot '..\..')).Path
+$modelPath = Join-Path $repoRoot 'docs\openup\model\skara-brae.eapx'
+if (-not (Test-Path $modelPath)) {
+    Write-Output "MISSING $modelPath - copy your EA installation's EABase.eapx there first (see docs/openup/model/README.md)"
+    exit 1
+}
+$realizationsPath = Join-Path $repoRoot 'docs\openup\model\exports\uc-realizations.json'
+$realizations = Get-Content $realizationsPath -Raw -Encoding UTF8 | ConvertFrom-Json
+
+$step = 'start'
+$app = $null
+$eaBefore = @(Get-Process -Name EA -ErrorAction SilentlyContinue | Select-Object -ExpandProperty Id)
+
+function Set-ScenarioSteps($scenario, $stepsData) {
+    foreach ($sd in $stepsData) {
+        $scenarioStep = $scenario.Steps.AddNew($sd.Text, $sd.Actor)
+        $null = $scenarioStep.Update()
+    }
+    $scenario.Steps.Refresh()
+    $null = $scenario.Update()
+    $null = $scenario.Update()
+}
+
+try {
+    $app = New-Object -ComObject EA.App
+    $app.Visible = $false
+    $repo = $app.Repository
+    $null = $repo.OpenFile($modelPath)
+
+    $step = 'rename model root'
+    $root = $repo.Models.GetAt([int]0)
+    if ($root.Name -ne 'Skara Brae') { $root.Name = 'Skara Brae'; $null = $root.Update() }
+
+    # ---------- Requirements tree ----------
+    $step = 'remove and recreate Requirements'
+    for ($i = 0; $i -lt $root.Packages.Count; $i++) {
+        if (($root.Packages.GetAt([int]$i)).Name -eq 'Requirements') {
+            $null = $root.Packages.DeleteAt([int]$i, $false)
+            $root.Packages.Refresh()
+            break
+        }
+    }
+    $requirements = $root.Packages.AddNew('Requirements', 'Package')
+    $null = $requirements.Update()
+    $root.Packages.Refresh()
+
+    $step = 'Vision package'
+    $vision = $requirements.Packages.AddNew('Vision', 'Package')
+    $vision.Notes = 'Product purpose and segments. Human-facing source: docs/openup/requirements/vision.md (markdown is the source of truth; this package carries purpose notes and links, not a full copy).'
+    $null = $vision.Update()
+    $requirements.Packages.Refresh()
+
+    $step = 'Supplementary Specifications package'
+    $supp = $requirements.Packages.AddNew('Supplementary Specifications', 'Package')
+    $supp.Notes = 'Non-functional requirements. Source: docs/openup/requirements/supplementary-specifications.md; one Requirement element per top-level section, Trace connectors only where the section names a use case.'
+    $null = $supp.Update()
+    $requirements.Packages.Refresh()
+    $suppSections = @(
+        @{ Name = 'SS-1 Performance / Scalability' },
+        @{ Name = 'SS-2 Reliability / Correctness' },
+        @{ Name = 'SS-3 Quality Gates (per-commit acceptance)' },
+        @{ Name = 'SS-4 Data' },
+        @{ Name = 'SS-5 Security' },
+        @{ Name = 'SS-6 Constraints' },
+        @{ Name = 'SS-7 Usability / API' }
+    )
+    foreach ($section in $suppSections) {
+        $element = $supp.Elements.AddNew($section.Name, 'Requirement')
+        $null = $element.Update()
+    }
+    $supp.Elements.Refresh()
+
+    # ---------- Use Case Model ----------
+    $step = 'remove and recreate Use Case Model'
+    for ($i = 0; $i -lt $requirements.Packages.Count; $i++) {
+        if (($requirements.Packages.GetAt([int]$i)).Name -eq 'Use Case Model') {
+            $null = $requirements.Packages.DeleteAt([int]$i, $false)
+            $requirements.Packages.Refresh()
+            break
+        }
+    }
+    $ucModel = $requirements.Packages.AddNew('Use Case Model', 'Package')
+    $ucModel.Notes = 'Actors, use cases and scenarios of the implemented server MVP. Source: docs/openup/requirements/use-case-model.md (normative for status codes and flows).'
+    $null = $ucModel.Update()
+    $requirements.Packages.Refresh()
+
+    $step = 'create actors'
+    $actors = @(
+        @{ Name = 'Player';        Notes = 'Authenticated user owning one or more characters (JWT role player).' },
+        @{ Name = 'Administrator'; Notes = 'Player with elevated rights (role = admin); may view any user''s and any character''s resources read-only.' },
+        @{ Name = 'Guest';         Notes = 'Unauthenticated caller; only register/login are open.' }
+    )
+    $elements = @{}
+    foreach ($actor in $actors) {
+        $element = $ucModel.Elements.AddNew($actor.Name, 'Actor')
+        $element.Notes = $actor.Notes
+        $null = $element.Update()
+        $elements[$actor.Name] = $element
+    }
+    $ucModel.Elements.Refresh()
+
+    $step = 'create use cases'
+    $useCases = @(
+        @{ Name = 'UC-01 Register Account';          Notes = 'Open registration. No precondition.' },
+        @{ Name = 'UC-02 Authenticate';              Notes = 'Login with name and password; issues a JWT with the user''s real role.' },
+        @{ Name = 'UC-03 Manage Characters';         Notes = 'Create, list and view characters. Admin may act for any user (read-only view).' },
+        @{ Name = 'UC-04 Browse Game Catalogue';     Notes = 'Races, classes, items (type/quality/slot filters), enemies, adventure zones from static game data.' },
+        @{ Name = 'UC-05 Train Stat';                Notes = 'Train a stat at a training ground; costs 1 energy + gold. Includes Regenerate Resources.' },
+        @{ Name = 'UC-06 Manage Equipment';          Notes = 'Equip from inventory / unequip back to inventory.' },
+        @{ Name = 'UC-07 Trade at Shop';             Notes = 'Buy from (always-stocked + rotating) shop stock or sell inventory items.' },
+        @{ Name = 'UC-08 Run Adventure';             Notes = 'Zone adventure with weighted enemy pick and turn-based combat. Includes Regenerate Resources, Resolve Combat. Exception: encounter references an unknown enemy -> 500 (post WI-2; previously a panic). WI-2 design driver (sb_core::adventure extraction).' },
+        @{ Name = 'UC-09 Heal at Temple';            Notes = 'Full or partial healing, cost = amount healed, minimum 1 gold.' },
+        @{ Name = 'UC-10 Practice Bard Song';        Notes = 'Set or clear the active bard song (Bard only, level-gated).' },
+        @{ Name = 'UC-11 Study Magic';               Notes = 'View spellbook, learn spell levels (1-7, gold cost), activate/clear the active spell. Caster classes only; spell level = (character level / 3) + 1, uncapped by code.' },
+        @{ Name = 'UC-12 Level Up at Review Board';  Notes = 'Manual level-up: XP threshold + gold cost (500 per next level), full resource restore on level-up.' }
+    )
+    foreach ($useCase in $useCases) {
+        $element = $ucModel.Elements.AddNew($useCase.Name, 'UseCase')
+        $element.Notes = $useCase.Notes
+        $null = $element.Update()
+        $elements[$useCase.Name] = $element
+    }
+    $ucModel.Elements.Refresh()
+
+    $step = 'create associations'
+    function Add-EaConnector([object]$clientName, [object]$supplierName, [string]$type, [string]$stereotype) {
+        $connector = ($elements[$clientName]).Connectors.AddNew('', $type)
+        $connector.ClientID = ($elements[$clientName]).ElementID
+        $connector.SupplierID = ($elements[$supplierName]).ElementID
+        if ($stereotype) { $connector.Stereotype = $stereotype }
+        $null = $connector.Update()
+        ($elements[$clientName]).Connectors.Refresh()
+    }
+    Add-EaConnector 'Guest' 'UC-01 Register Account' 'Association' ''
+    Add-EaConnector 'Guest' 'UC-02 Authenticate' 'Association' ''
+    foreach ($ucName in @('UC-03 Manage Characters', 'UC-04 Browse Game Catalogue', 'UC-05 Train Stat', 'UC-06 Manage Equipment', 'UC-07 Trade at Shop', 'UC-08 Run Adventure', 'UC-09 Heal at Temple', 'UC-10 Practice Bard Song', 'UC-11 Study Magic', 'UC-12 Level Up at Review Board')) {
+        Add-EaConnector 'Player' $ucName 'Association' ''
+    }
+    Add-EaConnector 'Administrator' 'UC-03 Manage Characters' 'Association' ''
+
+    $step = 'create scenarios'
+    $scenariosByUc = @{
+        'UC-01 Register Account' = @(
+            @{ Name = 'Main Success Scenario'; Type = 'Basic Path';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Guest submits name (3-32 chars) and password (>= 6 chars).'; Actor = 'Guest' },
+                   @{ Text = 'System verifies the name is unused -> 409 CONFLICT if taken.'; Actor = 'System' },
+                   @{ Text = 'System hashes the password (argon2), assigns the player role and the next id, persists the user.'; Actor = 'System' },
+                   @{ Text = 'System issues a JWT (HS256, player role) and returns {token, user_id, name, role}.'; Actor = 'System' } ) },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'name length invalid -> 400; password too short -> 400; name taken -> 409; hashing/token failure -> 500.'; Steps = @() }
+        )
+        'UC-02 Authenticate' = @(
+            @{ Name = 'Main Success Scenario'; Type = 'Basic Path';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Guest submits name and password.'; Actor = 'Guest' },
+                   @{ Text = 'System finds the user (401 if unknown) and verifies the password hash (401 on mismatch).'; Actor = 'System' },
+                   @{ Text = 'System issues a JWT carrying the user''s real role (admin/player) and returns {token, user_id, name, role}.'; Actor = 'System' } ) },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'unknown name or wrong password -> 401 UNAUTHORIZED; token creation failure -> 500.'; Steps = @() }
+        )
+        'UC-03 Manage Characters' = @(
+            @{ Name = 'Main Success Scenario (create)'; Type = 'Basic Path';
+               Notes = 'Admin may act for any user.';
+               Steps = @(
+                   @{ Text = 'Player submits character name, race, class for their user id.'; Actor = 'Player' },
+                   @{ Text = 'System validates the target user exists (404) and the trimmed name is 1-32 chars (400).'; Actor = 'System' },
+                   @{ Text = 'System rolls stats (d6+5 base 6-16 per stat +/- race modifiers), computes max HP/energy/nerve from class, grants starting gold (50) and level-1 class spells to casters.'; Actor = 'System' },
+                   @{ Text = 'System assigns the next character id, stores and persists the character; returns it fully.'; Actor = 'System' } ) },
+            @{ Name = 'list/view'; Type = 'Alternate';
+               Notes = 'Player lists their characters (Admin: any user''s); the system applies Regenerate Resources to each returned character and returns them. Viewing one character applies regen then returns it.'; Steps = @() },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'foreign user/character without admin role -> 403 FORBIDDEN; user/character not found -> 404; invalid name -> 400.'; Steps = @() }
+        )
+        'UC-04 Browse Game Catalogue' = @(
+            @{ Name = 'Main Success Scenario'; Type = 'Basic Path';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Player requests the catalogue: races, classes, items (optional type/quality/slot filters), enemies, or adventure zones.'; Actor = 'Player' },
+                   @{ Text = 'System returns static game data loaded from skara-brae-common JSON (class info is enriched with is_caster).'; Actor = 'System' } ) },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'single item by unknown id -> 404; filters may return an empty list (not an error).'; Steps = @() }
+        )
+        'UC-05 Train Stat' = @(
+            @{ Name = 'Main Success Scenario'; Type = 'Basic Path';
+               Notes = 'Precondition: character exists and caller may act on it.';
+               Steps = @(
+                   @{ Text = 'Player selects a training ground (strength / dexterity / constitution / intelligence / luck) and submits the stat name.'; Actor = 'Player' },
+                   @{ Text = 'System applies Regenerate Resources.'; Actor = 'System' },
+                   @{ Text = 'System checks energy >= 1 and gold >= training cost (cost grows ~1.3x per 10 stat points).'; Actor = 'System' },
+                   @{ Text = 'System deducts 1 energy and the gold cost, increments the stat; constitution training recomputes max HP (current HP clamped).'; Actor = 'System' },
+                   @{ Text = 'System persists and returns {success, message, character}.'; Actor = 'System' } ) },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'foreign character -> 403; character not found -> 404; not enough energy -> 422; not enough gold -> 422; unknown stat name -> 400.'; Steps = @() }
+        )
+        'UC-06 Manage Equipment' = @(
+            @{ Name = 'Main Success Scenario (equip)'; Type = 'Basic Path';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Player submits an item id from their inventory.'; Actor = 'Player' },
+                   @{ Text = 'System moves the item from inventory to its slot; a previously equipped item in that slot returns to inventory.'; Actor = 'System' },
+                   @{ Text = 'System persists and returns the updated character.'; Actor = 'System' } ) },
+            @{ Name = 'unequip'; Type = 'Alternate';
+               Notes = 'Player submits a slot name; the system moves the equipped item back to inventory.'; Steps = @() },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'foreign character -> 403; character/item not found -> 404; item not in inventory -> 400; nothing equipped in slot -> 400.'; Steps = @() }
+        )
+        'UC-07 Trade at Shop' = @(
+            @{ Name = 'Main Success Scenario (buy)'; Type = 'Basic Path';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Player views the shop: always-stocked items plus rotating stock (with quantities) alongside their inventory.'; Actor = 'Player' },
+                   @{ Text = 'Player submits buy + item id.'; Actor = 'Player' },
+                   @{ Text = 'System checks gold >= price (422), and for non-always-in-stock items decrements the limited stock (410 GONE if 0).'; Actor = 'System' },
+                   @{ Text = 'System deducts gold, adds the item to inventory, persists character and stock; returns {success, message, gold}.'; Actor = 'System' } ) },
+            @{ Name = 'sell'; Type = 'Alternate';
+               Notes = 'Player submits sell + item id; system removes the first matching inventory item, pays half the item value, increments shop stock for non-permanent items.'; Steps = @() },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'unknown action or item not owned (sell) -> 400; item not found -> 404; insufficient gold -> 422; stock exhausted -> 410.'; Steps = @() }
+        )
+        'UC-08 Run Adventure' = @(
+            @{ Name = 'Main Success Scenario'; Type = 'Basic Path';
+               Notes = 'Precondition: character exists and caller may act on it.';
+               Steps = @(
+                   @{ Text = 'Player requests an adventure for a zone (default skara_brae_streets).'; Actor = 'Player' },
+                   @{ Text = 'System validates the zone (404) and applies Regenerate Resources.'; Actor = 'System' },
+                   @{ Text = 'System refuses incapacitated characters (HP <= 0 -> 400) and characters with nerve below the zone cost (422); otherwise deducts the nerve cost.'; Actor = 'System' },
+                   @{ Text = 'System draws one enemy from the zone''s weighted encounter table.'; Actor = 'System' },
+                   @{ Text = 'System resolves turn-based combat: open-ended d100 attack rolls, OB vs DB, RoleMaster crit tables with level-gap damage caps, active bard song effects, active spell damage/heal per round.'; Actor = 'System' },
+                   @{ Text = 'On player victory: XP and gold per the enemy definition, character HP set to the last round''s defender HP, and loot dropped per-item chance rolls (only items existing in the catalogue).'; Actor = 'System' },
+                   @{ Text = 'On defeat: character HP set to 0; no rewards.'; Actor = 'System' },
+                   @{ Text = 'Spell-point upkeep is charged whenever a spell was active, win or lose.'; Actor = 'System' },
+                   @{ Text = 'System persists the character and returns {zone, enemy, combat_log, loot} (loot = item display names).'; Actor = 'System' } ) },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'foreign character -> 403; character/zone not found -> 404; incapacitated -> 400; insufficient nerve -> 422.'; Steps = @() },
+            @{ Name = 'Exception'; Type = 'Exception';
+               Notes = 'encounter references an unknown enemy (data error) -> 500 (post WI-2; previously a panic).'; Steps = @() }
+        )
+        'UC-09 Heal at Temple' = @(
+            @{ Name = 'Main Success Scenario'; Type = 'Basic Path';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Player requests healing, optionally partial.'; Actor = 'Player' },
+                   @{ Text = 'System computes missing HP; full heals all, partial heals half (rounded up); cost = amount healed, minimum 1 gold.'; Actor = 'System' },
+                   @{ Text = 'System checks gold (422), deducts it, restores HP, persists; returns {hp, max_hp, gold, healed: true}.'; Actor = 'System' } ) },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'foreign character -> 403; not found -> 404; already at full HP -> 400; insufficient gold -> 422.'; Steps = @() }
+        )
+        'UC-10 Practice Bard Song' = @(
+            @{ Name = 'Main Success Scenario'; Type = 'Basic Path';
+               Notes = 'Precondition: character class is Bard.';
+               Steps = @(
+                   @{ Text = 'Player views available songs (level-gated, with combat effect descriptions) and the active song.'; Actor = 'Player' },
+                   @{ Text = 'Player submits a song id; system validates level requirement (422) and sets it active; returns {success, message, active_song}.'; Actor = 'Player' } ) },
+            @{ Name = 'clear'; Type = 'Alternate';
+               Notes = 'submitting no song id clears the active song.'; Steps = @() },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'non-Bard -> 403; unknown song -> 404; level too low -> 422; foreign character -> 403; not found -> 404.'; Steps = @() }
+        )
+        'UC-11 Study Magic' = @(
+            @{ Name = 'Main Success Scenario (view spellbook)'; Type = 'Basic Path';
+               Notes = 'Precondition: character belongs to a caster class (Mage->magician, Wizard, Conjurer, Sorcerer). Spell level = (character level / 3) + 1 - uncapped by code (level 100 -> spell level 34); learn requests are validated to 1-7.';
+               Steps = @(
+                   @{ Text = 'Player requests their spellbook: caster class, current spell level, spell points, spells up to the achievable level (each marked known), and the learn-cost table for levels 2-7.'; Actor = 'Player' } ) },
+            @{ Name = 'learn spell level'; Type = 'Alternate';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Player submits a spell level (1-7).'; Actor = 'Player' },
+                   @{ Text = 'System validates caster class (403), level range (400), level not above the character''s current spell level (422), gold >= learn cost (422), and that new spells exist (400).'; Actor = 'System' },
+                   @{ Text = 'System deducts gold, adds all unknown spell ids of that level, recomputes and refills max spell points; returns {learned_count, spell_points, max_spell_points, gold}.'; Actor = 'System' } ) },
+            @{ Name = 'activate/clear active spell'; Type = 'Alternate';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Player submits a spell id (or empty to clear).'; Actor = 'Player' },
+                   @{ Text = 'System validates the spell is known (403), exists (404), and spell points suffice (422); deducts the spell''s points and sets it active; returns {active_spell, spell_points}.'; Actor = 'System' } ) }
+        )
+        'UC-12 Level Up at Review Board' = @(
+            @{ Name = 'Main Success Scenario'; Type = 'Basic Path';
+               Notes = '';
+               Steps = @(
+                   @{ Text = 'Player requests a level-up.'; Actor = 'Player' },
+                   @{ Text = 'System validates: below max level 100, XP >= 18*100*(level)^2 for the next level (i.e. xp_for_level(next)), gold >= 500*next level.'; Actor = 'System' },
+                   @{ Text = 'System deducts the gold cost, increments the level, recomputes and fully restores HP/energy/nerve and max spell points; persists; returns {success, message, character}.'; Actor = 'System' } ) },
+            @{ Name = 'Alternate flows'; Type = 'Alternate';
+               Notes = 'already at max level; not enough XP; not enough gold -> all 422. Foreign character -> 403; not found -> 404.'; Steps = @() }
+        )
+    )
+    foreach ($useCase in $useCases) {
+        $ucElement = $elements[$useCase.Name]
+        foreach ($scenarioData in $scenariosByUc[$useCase.Name]) {
+            $scenario = $ucElement.Scenarios.AddNew($scenarioData.Name, $scenarioData.Type)
+            $scenario.Notes = $scenarioData.Notes
+            $null = $scenario.Update()
+            Set-ScenarioSteps $scenario $scenarioData.Steps
+        }
+        $ucElement.Scenarios.Refresh()
+        $null = $ucElement.Update()
+    }
+
+    $step = 'create use case overview diagram'
+    $diagram = $ucModel.Diagrams.AddNew('Skara Brae Use Case Overview', 'UseCase')
+    $diagram.Notes = 'Actor-to-use-case overview of the implemented server MVP.'
+    $null = $diagram.Update()
+    $ucModel.Diagrams.Refresh()
+    $diagram = $ucModel.Diagrams.GetByName('Skara Brae Use Case Overview')
+    $actorY = 40
+    foreach ($actor in $actors) {
+        $diagramObject = $diagram.DiagramObjects.AddNew('', '')
+        $diagramObject.ElementID = ($elements[$actor.Name]).ElementID
+        $diagramObject.left = 40; $diagramObject.right = 130
+        $diagramObject.top = $actorY; $diagramObject.bottom = $actorY + 60
+        $null = $diagramObject.Update()
+        $actorY += 200
+    }
+    $ucX = 400; $ucY = 40
+    foreach ($useCase in $useCases) {
+        $diagramObject = $diagram.DiagramObjects.AddNew('', '')
+        $diagramObject.ElementID = ($elements[$useCase.Name]).ElementID
+        $diagramObject.left = $ucX; $diagramObject.right = $ucX + 300
+        $diagramObject.top = $ucY; $diagramObject.bottom = $ucY + 60
+        $null = $diagramObject.Update()
+        $ucY += 100
+    }
+    $null = $diagram.Update()
+
+    # ---------- Analysis-Design tree ----------
+    $step = 'remove and recreate Analysis-Design'
+    for ($i = 0; $i -lt $root.Packages.Count; $i++) {
+        if (($root.Packages.GetAt([int]$i)).Name -eq 'Analysis-Design') {
+            $null = $root.Packages.DeleteAt([int]$i, $false)
+            $root.Packages.Refresh()
+            break
+        }
+    }
+    $analysisDesign = $root.Packages.AddNew('Analysis-Design', 'Package')
+    $null = $analysisDesign.Update()
+    $root.Packages.Refresh()
+
+    $step = 'Architecture Overview package'
+    $architecture = $analysisDesign.Packages.AddNew('Architecture Overview', 'Package')
+    $architecture.Notes = 'Dependency rule (Clean Architecture): all controllers/entities live in sb-core/sb-shared (domain side, no HTTP imports); all boundaries live in sb-api. The single current violations (ShopService, HealingService, parts of MagicService in sb-api) are recorded as debt with a follow-up question - the model must not paper over them (stale docs are defects). Boundary rules: design note §3.'
+    $null = $architecture.Update()
+    $analysisDesign.Packages.Refresh()
+    $crossCutting = @(
+        @{ Name = 'DomainError'; Notes = 'sb-core::error::DomainError + sb-api::routes::domain_status (status mapping table, design note §4.1) realize the error paths of UC-05/06/08/12.' },
+        @{ Name = 'Constants';   Notes = 'sb-core::constants realizes NFR "no magic numbers".' },
+        @{ Name = 'Responses';   Notes = 'sb-api::routes::responses realizes NFR-19 (wire-format freeze).' }
+    )
+    foreach ($crossElement in $crossCutting) {
+        $element = $architecture.Elements.AddNew($crossElement.Name, 'Class')
+        $element.Notes = $crossElement.Notes
+        $null = $element.Update()
+    }
+    $architecture.Elements.Refresh()
+
+    $step = 'UC realization packages (from exports/uc-realizations.json)'
+    foreach ($realization in $realizations.realizations) {
+        $realizationPackage = $analysisDesign.Packages.AddNew($realization.id, 'Package')
+        $null = $realizationPackage.Update()
+        $analysisDesign.Packages.Refresh()
+
+        $collaboration = $realizationPackage.Elements.AddNew($realization.id, 'Collaboration')
+        $null = $collaboration.Update()
+        $realizationPackage.Elements.Refresh()
+        $connector = $collaboration.Connectors.AddNew('', 'Realization')
+        $connector.ClientID = $collaboration.ElementID
+        $connector.SupplierID = ($elements[$realization.useCase]).ElementID
+        $null = $connector.Update()
+        $collaboration.Connectors.Refresh()
+
+        foreach ($mappingElement in $realization.elements) {
+            $classElement = $realizationPackage.Elements.AddNew($mappingElement.name, 'Class')
+            $classElement.Stereotype = $mappingElement.stereotype
+            $classElement.Notes = "Design element: $($mappingElement.designElement). $($mappingElement.notes)"
+            $null = $classElement.Update()
+        }
+        $realizationPackage.Elements.Refresh()
+
+        $realizationDiagram = $realizationPackage.Diagrams.AddNew($realization.id, 'Class')
+        $null = $realizationDiagram.Update()
+        $realizationPackage.Diagrams.Refresh()
+        $diagramObj = $realizationPackage.Diagrams.GetByName($realization.id)
+        $classY = 40
+        foreach ($mappingElement in $realization.elements) {
+            $placed = $false
+            for ($e = 0; $e -lt $realizationPackage.Elements.Count; $e++) {
+                $candidate = $realizationPackage.Elements.GetAt([int]$e)
+                if ($candidate.Name -eq $mappingElement.name -and $candidate.Type -eq 'Class') {
+                    $do = $diagramObj.DiagramObjects.AddNew('', '')
+                    $do.ElementID = $candidate.ElementID
+                    $do.left = 40; $do.right = 300
+                    $do.top = $classY; $do.bottom = $classY + 60
+                    $null = $do.Update()
+                    $classY += 100
+                    $placed = $true
+                    break
+                }
+            }
+            if (-not $placed) { throw "class not found in $($realization.id): $($mappingElement.name)" }
+        }
+        $null = $diagramObj.Update()
+    }
+
+    # ---------- verify ----------
+    $step = 'verify'
+    $null = $repo.CloseFile()
+    $null = $repo.OpenFile($modelPath)
+    $checkUc = $repo.Models.GetAt([int]0).Packages.GetByName('Requirements').Packages.GetByName('Use Case Model')
+    $checkUc.Elements.Refresh()
+    $actorCount = 0; $ucCount = 0
+    for ($i = 0; $i -lt $checkUc.Elements.Count; $i++) {
+        $element = $checkUc.Elements.GetAt([int]$i)
+        if ($element.Type -eq 'Actor') { $actorCount++ }
+        if ($element.Type -eq 'UseCase') { $ucCount++ }
+    }
+    $checkAd = $repo.Models.GetAt([int]0).Packages.GetByName('Analysis-Design')
+    $checkAd.Packages.Refresh()
+    $realizationCount = 0
+    for ($i = 0; $i -lt $checkAd.Packages.Count; $i++) {
+        if (($checkAd.Packages.GetAt([int]$i)).Name -like 'UC-?? Realization') { $realizationCount++ }
+    }
+    Write-Output "VERIFY actors=$actorCount (expect 3), useCases=$ucCount (expect 12), realizationPackages=$realizationCount (expect 12)"
+    if ($actorCount -ne 3 -or $ucCount -ne 12 -or $realizationCount -ne 12) { Write-Output 'VERIFY FAILED'; exit 1 }
+    $null = $repo.CloseFile()
+    Write-Output 'ALL STEPS OK - save the model in EA if prompted, then run export-model.ps1 and BUILD-CHECKLIST.md §4'
+}
+catch {
+    Write-Output "FAILED at [$step]: $($_.Exception.Message)"
+    exit 1
+}
+finally {
+    Get-Process -Name EA -ErrorAction SilentlyContinue |
+        Where-Object { $eaBefore -notcontains $_.Id } |
+        ForEach-Object { Stop-Process -Id $_.Id -Force }
+}
diff --git a/scripts/openup/export-model.ps1 b/scripts/openup/export-model.ps1
new file mode 100644
index 0000000..b99c953
--- /dev/null
+++ b/scripts/openup/export-model.ps1
@@ -0,0 +1,171 @@
+# Skara Brae — EA model exporter (WI-2), adapted from keyfob-station's
+# export-model-json.ps1 (COM walk of the model -> machine-readable JSON).
+#
+# Regenerates (generated files — never hand-edit):
+#   docs/openup/model/exports/use-case-model.json   (actors, use cases, scenarios, steps)
+#   docs/openup/model/exports/uc-realizations.json  (realization packages + elements)
+#   docs/openup/model/exports/xmi-backup.xml        (lossless EA XMI 2.1 export of the root)
+#
+# Drift rule: markdown (use-case-model.md, uc-realization-mapping.md) and the model must
+# agree; a mismatch is a defect fixed in the same cycle. uc-realizations.json content must
+# match what scripts/openup/markdown-to-json.py generated from mapping §2.
+#
+# Platform: Windows + installed EA (design §11.c). If COM automation hits friction, the
+# fallback is EA's manual Publish -> XML export into exports/ (see model/README.md).
+
+$ErrorActionPreference = 'Stop'
+
+$repoRoot    = (Resolve-Path (Join-Path $PSScriptRoot '..\..')).Path
+$modelPath   = Join-Path $repoRoot 'docs\openup\model\skara-brae.eapx'
+if (-not (Test-Path $modelPath)) {
+    Write-Output "MISSING $modelPath - nothing to export"
+    exit 1
+}
+$exportsDir  = Join-Path $repoRoot 'docs\openup\model\exports'
+New-Item -ItemType Directory -Force -Path $exportsDir | Out-Null
+$ucOutPath   = Join-Path $exportsDir 'use-case-model.json'
+$realOutPath = Join-Path $exportsDir 'uc-realizations.json'
+$xmiOutPath  = Join-Path $exportsDir 'xmi-backup.xml'
+
+$app = $null
+$eaBefore = @(Get-Process -Name EA -ErrorAction SilentlyContinue | Select-Object -ExpandProperty Id)
+try {
+    $app = New-Object -ComObject EA.App
+    $app.Visible = $false
+    $repo = $app.Repository
+    $null = $repo.OpenFile($modelPath)
+    $root = $repo.Models.GetAt([int]0)
+
+    # ---------- Requirements / Use Case Model ----------
+    $ucModel = $root.Packages.GetByName('Requirements').Packages.GetByName('Use Case Model')
+
+    $actors = @()
+    $useCases = @()
+    for ($i = 0; $i -lt $ucModel.Elements.Count; $i++) {
+        $element = $ucModel.Elements.GetAt([int]$i)
+        if ($element.Type -eq 'Actor') {
+            $actors += [ordered]@{ name = $element.Name; notes = $element.Notes }
+        }
+    }
+
+    for ($i = 0; $i -lt $ucModel.Elements.Count; $i++) {
+        $element = $ucModel.Elements.GetAt([int]$i)
+        if ($element.Type -ne 'UseCase') { continue }
+
+        $associatedActors = @()
+        for ($c = 0; $c -lt $element.Connectors.Count; $c++) {
+            $connector = $element.Connectors.GetAt([int]$c)
+            if ($connector.Type -ne 'Association') { continue }
+            $otherId = if ($connector.ClientID -eq $element.ElementID) { $connector.SupplierID } else { $connector.ClientID }
+            $other = $repo.GetElementByID($otherId)
+            if ($other.Type -eq 'Actor') { $associatedActors += $other.Name }
+        }
+
+        $scenarios = @()
+        $element.Scenarios.Refresh()
+        for ($s = 0; $s -lt $element.Scenarios.Count; $s++) {
+            $scenario = $element.Scenarios.GetAt([int]$s)
+            $steps = @()
+            $scenario.Steps.Refresh()
+            for ($t = 0; $t -lt $scenario.Steps.Count; $t++) {
+                $scenarioStep = $scenario.Steps.GetAt([int]$t)
+                $steps += [ordered]@{ actor = $scenarioStep.StepType; text = $scenarioStep.Name }
+            }
+            $scenarios += [ordered]@{
+                name  = $scenario.Name
+                type  = $scenario.Type
+                notes = $scenario.Notes
+                steps = $steps
+            }
+        }
+
+        $useCases += [ordered]@{
+            name      = $element.Name
+            notes     = $element.Notes
+            actors    = $associatedActors
+            scenarios = $scenarios
+        }
+    }
+
+    $ucPayload = [ordered]@{
+        exportedFrom = 'docs/openup/model/skara-brae.eapx (Requirements/Use Case Model)'
+        actors       = $actors
+        useCases     = $useCases
+    }
+    [System.IO.File]::WriteAllText($ucOutPath, ($ucPayload | ConvertTo-Json -Depth 8), [System.Text.Encoding]::UTF8)
+    Write-Output "exported: $ucOutPath ($($useCases.Count) use cases, $($actors.Count) actors)"
+
+    # ---------- Analysis-Design realizations ----------
+    $analysisDesign = $root.Packages.GetByName('Analysis-Design')
+    $realizations = @()
+    for ($p = 0; $p -lt $analysisDesign.Packages.Count; $p++) {
+        $realizationPackage = $analysisDesign.Packages.GetAt([int]$p)
+        if ($realizationPackage.Name -notlike 'UC-?? Realization') { continue }
+        $realizationPackage.Elements.Refresh()
+
+        $useCaseName = ''
+        $classes = @()
+        for ($e = 0; $e -lt $realizationPackage.Elements.Count; $e++) {
+            $element = $realizationPackage.Elements.GetAt([int]$e)
+            if ($element.Type -eq 'Collaboration') {
+                $element.Connectors.Refresh()
+                for ($c = 0; $c -lt $element.Connectors.Count; $c++) {
+                    $connector = $element.Connectors.GetAt([int]$c)
+                    if (($connector.Type -eq 'Realization' -or $connector.Type -eq 'Realisation') -and $connector.ClientID -eq $element.ElementID) {
+                        $useCaseName = $repo.GetElementByID($connector.SupplierID).Name
+                    }
+                }
+            }
+            if ($element.Type -eq 'Class') {
+                $classes += [ordered]@{
+                    name          = $element.Name
+                    stereotype    = $element.Stereotype
+                    notes         = $element.Notes
+                }
+            }
+        }
+        $realizations += [ordered]@{
+            id       = $realizationPackage.Name
+            useCase  = $useCaseName
+            elements = $classes
+        }
+    }
+
+    $architecture = $analysisDesign.Packages.GetByName('Architecture Overview')
+    $architecture.Elements.Refresh()
+    $crossCutting = @()
+    for ($e = 0; $e -lt $architecture.Elements.Count; $e++) {
+        $element = $architecture.Elements.GetAt([int]$e)
+        $crossCutting += [ordered]@{ name = $element.Name; notes = $element.Notes }
+    }
+
+    $realPayload = [ordered]@{
+        exportedFrom = 'docs/openup/model/skara-brae.eapx (Analysis-Design realization packages)'
+        realizations = $realizations
+        crossCutting = $crossCutting
+    }
+    [System.IO.File]::WriteAllText($realOutPath, ($realPayload | ConvertTo-Json -Depth 8), [System.Text.Encoding]::UTF8)
+    Write-Output "exported: $realOutPath ($($realizations.Count) realizations)"
+
+    # ---------- lossless XMI backup ----------
+    try {
+        $project = $repo.GetProjectInterface()
+        $null = $project.ExportPackageXMI($root.PackageGUID, $xmiOutPath, 1, 0)
+        Write-Output "exported: $xmiOutPath (XMI 2.1 backup of model root '$($root.Name)')"
+    }
+    catch {
+        Write-Output "WARNING: XMI export failed ($($_.Exception.Message)); use EA Publish -> XML manually per model/README.md option 2"
+    }
+
+    $null = $repo.CloseFile()
+    Write-Output 'EXPORT OK - review the exports diff, then commit .eapx + exports/ + scripts/openup/ as one commit'
+}
+catch {
+    Write-Output "FAILED: $($_.Exception.ToString())"
+    exit 1
+}
+finally {
+    Get-Process -Name EA -ErrorAction SilentlyContinue |
+        Where-Object { $eaBefore -notcontains $_.Id } |
+        ForEach-Object { Stop-Process -Id $_.Id -Force }
+}
diff --git a/scripts/openup/markdown-to-json.py b/scripts/openup/markdown-to-json.py
new file mode 100644
index 0000000..8a9df99
--- /dev/null
+++ b/scripts/openup/markdown-to-json.py
@@ -0,0 +1,149 @@
+#!/usr/bin/env python3
+"""Generate the machine-readable OpenUP model intermediates from the markdown sources.
+
+Transforms the approved OpenUP artifacts (never hand-edited exports):
+  docs/openup/analysis-design/uc-realization-mapping.md  (§2 table)
+  docs/openup/requirements/use-case-model.md             (canonical UC names)
+into:
+  docs/openup/model/exports/uc-realizations.json
+
+The use-case-model.json intermediate is NOT produced here: the markdown does not
+carry per-step actor tags, so a faithful transformation requires the EA session
+(export-model.ps1) or staged decisions. See docs/openup/model/README.md.
+
+Runs on the standard library only (Linux, no EA/COM required).
+"""
+
+import json
+import re
+import sys
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+MAPPING_MD = REPO_ROOT / "docs/openup/analysis-design/uc-realization-mapping.md"
+UC_MODEL_MD = REPO_ROOT / "docs/openup/requirements/use-case-model.md"
+OUTPUT_JSON = REPO_ROOT / "docs/openup/model/exports/uc-realizations.json"
+
+UC_ID_PATTERN = re.compile(r"^(UC-\d{2})\s*(.*)$")
+
+
+def canonical_use_case_names() -> dict[str, str]:
+    """UC id -> full use case name, from the use-case-model.md overview table."""
+    names: dict[str, str] = {}
+    for line in UC_MODEL_MD.read_text(encoding="utf-8").splitlines():
+        cells = [cell.strip() for cell in line.strip().strip("|").split("|")]
+        if len(cells) < 2:
+            continue
+        match = UC_ID_PATTERN.match(cells[0])
+        if match:
+            names[match.group(1)] = cells[1]
+    if len(names) != 12:
+        raise SystemExit(
+            f"expected 12 use cases in {UC_MODEL_MD}, found {len(names)}"
+        )
+    return names
+
+
+def split_table_row(line: str) -> list[str]:
+    return [cell.strip() for cell in line.strip().strip("|").split("|")]
+
+
+def is_table_row(line: str) -> bool:
+    return line.strip().startswith("|") and line.strip().endswith("|")
+
+
+def parse_realization_table(mapping_text: str) -> tuple[list[dict], dict[str, str]]:
+    """Parse the §2 mapping table into per-UC realization entries.
+
+    Returns (realizations, paragraphs) where paragraphs carries the verbatim
+    cross-cutting and dependency-rule paragraphs that follow the table.
+    """
+    lines = mapping_text.splitlines()
+    section_started = False
+    realizations: list[dict] = []
+    current: dict | None = None
+
+    for index, line in enumerate(lines):
+        if line.startswith("## 2. UC realization mapping"):
+            section_started = True
+            continue
+        if not section_started:
+            continue
+        if line.startswith("## 3."):
+            break
+        if not is_table_row(line):
+            continue
+        cells = split_table_row(line)
+        if cells[0] and set(cells[0]) <= {"-", " ", ":"}:
+            continue
+        if cells[0] in ("UC", "Analysis class"):
+            continue
+
+        uc_cell = cells[0]
+        element = {
+            # Emphasis markers are formatting, not content; element names are
+            # identifiers (e.g. **AdventureService** -> AdventureService).
+            # All other cells stay verbatim.
+            "name": cells[1].replace("**", ""),
+            "stereotype": cells[2],
+            "designElement": cells[3],
+            "notes": cells[4] if len(cells) > 4 else "",
+        }
+        id_match = UC_ID_PATTERN.match(uc_cell)
+        if id_match:
+            current = {"id": f"{id_match.group(1)} Realization", "useCaseId": id_match.group(1), "elements": [element]}
+            realizations.append(current)
+        elif uc_cell == "" and current is not None:
+            current["elements"].append(element)
+        else:
+            raise SystemExit(f"unparseable mapping row {index + 1}: {line!r}")
+
+    paragraphs = {}
+    for paragraph_key, paragraph_prefix in (
+        ("crossCutting", "Cross-cutting design elements"),
+        ("dependencyRule", "Dependency rule check"),
+    ):
+        paragraphs[paragraph_key] = next(
+            (line for line in lines if line.startswith(paragraph_prefix)), ""
+        )
+    return realizations, paragraphs
+
+
+def build_payload() -> dict:
+    canonical_names = canonical_use_case_names()
+    realizations, paragraphs = parse_realization_table(
+        MAPPING_MD.read_text(encoding="utf-8")
+    )
+    if len(realizations) != 12:
+        raise SystemExit(
+            f"expected 12 realizations in {MAPPING_MD}, found {len(realizations)}"
+        )
+    for realization in realizations:
+        realization["useCase"] = canonical_names[realization.pop("useCaseId")]
+    return {
+        "exportedFrom": (
+            "docs/openup/analysis-design/uc-realization-mapping.md §2, generated by "
+            "scripts/openup/markdown-to-json.py — generated file, never hand-edit"
+        ),
+        "realizations": realizations,
+        "crossCutting": paragraphs["crossCutting"],
+        "dependencyRule": paragraphs["dependencyRule"],
+    }
+
+
+def main() -> int:
+    payload = build_payload()
+    OUTPUT_JSON.parent.mkdir(parents=True, exist_ok=True)
+    OUTPUT_JSON.write_text(
+        json.dumps(payload, indent=2, ensure_ascii=False) + "\n", encoding="utf-8"
+    )
+    element_count = sum(len(r["elements"]) for r in payload["realizations"])
+    print(
+        f"wrote {OUTPUT_JSON.relative_to(REPO_ROOT)}: "
+        f"{len(payload['realizations'])} realizations, {element_count} elements"
+    )
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())