docs(plan-3): close out Plan 3 — BACKLOG entries, RFC status, primitives registry, tooling conventions

- BACKLOG: add 3 spawned follow-ups (EnergyDots NaN, DraggableBlock pointercancel, AD-3 Menubar a11y)
- RFC-WS-GUI-REDESIGN-CREWLI-STARTER: mark Plan 3 complete with commit refs + DoD ledger
- PRIMEVUE_COMPONENTS: v2 primitives registry (8 components), statusSeverity SoT, Menubar-wrap pattern
- ARCH-TESTING: mount-helper type convention (Plan 3 codified, Plan 4 carry-over)
- FRONTEND-TOOLING: scoped lint invocation note (DoD #13 root cause)
- AppDialog.stories.ts: rename title to 'Shared/AppDialog' for sibling consistency

dev-docs/ARCH-TESTING.md

@@ -340,3 +340,30 @@ For Playwright tests to run, the host must have:
   for v1 per RFC §A.5.
 - Mobile viewport baselines — desktop 1440×900 only for v1.
 - Soketi / WebSocket testing infrastructure when ART-15 lands.
+
+---
+
+## Mount-helper type convention (Plan 3 codified)
+
+Plan 3 hit this in 6+ tasks: a plan-doc test spec typed the `mount`
+helper's props parameter as `Record<string, unknown>`, which `vue-tsc`
+strict mode rejects when the object is passed to
+`mount(Component, { props })` — the component's generated prop type is
+narrower than `Record<string, unknown>`, so the assignment is a type
+error (and widening it with `any` would violate the project zero-`any`
+rule).
+
+**Convention:** type the helper parameter as `Partial<<Component>Props>`,
+never `Record<string, unknown>`:
+
+```ts
+const mountX = (props: Partial<XProps> = {}) =>
+  mount(X, { props })
+```
+
+Rationale: satisfies `vue-tsc` strict; behaviour-neutral; introduces no
+`any`. Plan 3 used the equivalent explicit inline props shape per task
+(the behaviour-neutral sanctioned deviation from the verbatim plan-doc);
+**standardise on `Partial<<Component>Props>` from Plan 4 onward** so the
+template-layer tests (List / Form / Detail / Dashboard / StateBlock)
+share one idiom rather than re-deriving the shape each time.