openup: doc restructure - template alignment + design sequences (non-PSP)

Align the OpenUP markdown set to the blank templates (process-data repo,
templates/openup/) per BUILD-CHECKLIST 7. Scenario step text unchanged;
the EA model needs no change (brief descriptions already live in the
model's UC/actor notes).

- vision.md: positioning tables, stakeholder summary, user environment,
  needs-and-features table (R1/R2), other product requirements
- use-case-model.md: per-UC specification sections (brief description,
  actor descriptions, named alternative/exception subsections with
  numbered steps, post-conditions, special requirements)
- supplementary-specifications.md: category tables with priority and
  use-case columns + reverse coverage matrix; IDs unchanged
- test/quality-check-procedure.md: migrated from Joplin (single content
  home); stale open items marked resolved (WI-1/WI-2)
- analysis-design/sequences/: 12 PlantUML design sequences (lifelines =
  analysis classes, messages = design elements; per the PlantUML layout
  style guide) + PNG renders; embedded in Architecture Notebook 9.3
- Joplin consolidated: project content notes deleted (all live in
  docs/game + docs/openup); Joplin keeps the status note only

docs/openup/analysis-design/sequences/uc-11-study-magic.puml

@@ -0,0 +1,51 @@
+@startuml uc-11-study-magic
+autonumber
+title UC-11 Study Magic (design sequence)
+actor Player
+participant "MagicBoundary\n«/api/characters/{id}/spells»" as boundary <<boundary>>
+participant "MagicService\nsb-api::routes::{get_spells,learn}" as control <<control>>
+participant "Spell\nSpellDef + known/active/points" as entity <<entity>>
+
+== View spellbook ==
+Player -> boundary : GET spells
+boundary -> control : get_spells(character)
+control -> entity : caster class, spell level = (level/3)+1
+control --> boundary : spells (marked known) + learn costs 2-7
+boundary --> Player : spellbook + spell points
+
+== Learn spell level ==
+Player -> boundary : POST learn level (1-7)
+boundary -> control : learn_spell_level(character, level)
+alt non-caster
+  control --> boundary : 403
+else level out of 1-7
+  control --> boundary : 400
+else level above current spell level
+  control --> boundary : 422
+else gold < learn cost
+  control --> boundary : 422
+else no new spells at level
+  control --> boundary : 400
+else ok
+  control -> entity : gold -= cost, add unknown spell ids
+  control -> entity : recompute + refill max spell points, persist
+  control --> boundary : {learned_count, spell_points, max_spell_points, gold}
+  boundary --> Player : {learned_count, ...}
+end
+
+== Activate / Clear active spell ==
+Player -> boundary : POST spell id (or empty)
+boundary -> control : activate_spell(character, spell)
+alt spell not known
+  control --> boundary : 403
+else spell unknown
+  control --> boundary : 404
+else spell points insufficient
+  control --> boundary : 422
+else ok
+  control -> entity : points -= cost, active_spell = spell, persist
+  control --> boundary : {active_spell, spell_points}
+  boundary --> Player : {active_spell, spell_points}
+end
+note over entity : active spell acts in UC-08 combat\n(dmg/heal per round + upkeep)
+@enduml