Add in-app confirmation dialog replacing window.confirm

AGENTS.md

@@ -50,18 +50,22 @@ external repo is needed to work from them.
 
 ```
 src/
+├── main.tsx         # App entry (font wiring, startup, render)
 ├── core/            # Portable spec engine (no browser/React/Monaco)
 ├── app/
 │   ├── components/  # React UI (CSS Modules co-located)
-│   ├── stores/      # Zustand stores
+│   ├── hooks/       # Reusable React hooks (e.g. useFocusTrap — shared by overlays)
+│   ├── stores/      # Zustand stores (incl. ConfirmStore — in-app confirm dialogs)
 │   ├── services/    # Business logic
 │   ├── orchestration/   # Startup wiring: store↔adapter subscribers (persistence)
-│   └── infrastructure/  # IndexedDB, localStorage, URL hash adapters
+│   └── infrastructure/  # IndexedDB, localStorage, Monaco, settings adapters
 styles/              # Global CSS (tokens, base)
 docs/
 ├── spec/            # Authoritative behavioral specification (00–10) — the WHAT
 ├── architecture/    # Architecture playbook (00–09) — the HOW (self-contained)
-└── IMPLEMENTATION-PLAN.md
+│   └── visual-specimen.html  # Standalone token sandbox + reusable-primitive catalog
+├── IMPLEMENTATION-PLAN.md    # Milestone sequence (M0–M6)
+└── WHY-A-SEPARATE-REBUILD.md
 ```
 
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