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-04-browse-catalogue.puml

@@ -0,0 +1,17 @@
+@startuml uc-04-browse-catalogue
+autonumber
+title UC-04 Browse Game Catalogue (design sequence)
+actor Player
+participant "CatalogueBrowser\n«/api/{races,classes,items,enemies,adventures}»" as boundary <<boundary>>
+participant "GameData\nsb-core::data + items" as entity <<entity>>
+
+== Browse ==
+Player -> boundary : GET catalogue (optional type/quality/slot filters)
+boundary -> entity : read LazyLock catalogue (sb-common JSON)
+alt unknown item id
+  entity --> boundary : 404
+else hit (possibly empty filter result)
+  entity --> boundary : static data (classes + is_caster)
+  boundary --> Player : races / classes / items / enemies / zones
+end
+@enduml