docs(ui): finalize MVP plan structure and de-archaeologize topic docs

MVP web client (Phases 1-30) is complete; reorganize planning + living docs around that.

- PLAN.md kept as the staged MVP record (1-30) with a status block + pointers; removed the 31-36 stages, regression scenarios, and deferred-TODO section (moved out); fixed a stale cross-machine plan path.

- ui/PLAN-finalize.md (new): active web-finalization plan in 8 stages (visual system, a11y, i18n, error UX, PWA, build hygiene, docs, owner manual-QA loop); absorbs former Phases 33 and 35.

- ui/ROADMAP.md (new): post-MVP (Wails, Capacitor, realistic projection, acceptance + regression scenarios) and triaged deferred follow-ups.

- ui/docs/README.md (new): grouped topic-doc index.

- De-archaeologized all 20 ui/docs topic docs + ui/README.md + ui/core/README.md: stripped Phase-N build history, rewritten as current-state; deferred work now points at ROADMAP.md / PLAN-finalize.md. Docs-only; no code change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ui/docs/testing.md

@@ -2,8 +2,7 @@
 
 UI client test toolchain. Project-wide testing layers (service /
 inter-service / system) live in [`../../docs/TESTING.md`](../../docs/TESTING.md);
-this doc only covers the UI-specific tiers added in Phase 2 of
-[`../PLAN.md`](../PLAN.md).
+this doc covers the UI-specific tiers.
 
 ## Tier 1 — per-PR
 
@@ -45,17 +44,18 @@ as Gitea Actions artefacts (`playwright-report` and `playwright-traces`,
 
 Triggered by `.gitea/workflows/ui-release.yaml` on tag push (`v*`).
 Currently mirrors the Tier 1 step set; the dedicated release-only
-checks land in later phases:
+checks are deferred:
 
-- **Visual regression baseline check** — Phase 33. Snapshots live in
+- **Visual regression baseline check** — deferred to the
+  finalization plan (../Plan-finalize.md). Snapshots will live in
   `ui/frontend/tests/__snapshots__/` until the project shifts to
   Argos or another visual-diff service.
-- **iOS smoke (Capacitor + Appium)** — Phase 32. Runs on a `macos-13`
-  runner once the Capacitor mobile wrapper exists.
+- **iOS smoke (Capacitor + Appium)** — planned (see ../ROADMAP.md).
+  Runs on a `macos-13` runner once the Capacitor mobile wrapper
+  exists.
 
 Both blocks are present as commented sections in
-`.gitea/workflows/ui-release.yaml` with the phase number that
-re-enables them.
+`.gitea/workflows/ui-release.yaml`.
 
 ## Local execution
 
@@ -150,8 +150,7 @@ In synthetic mode:
   same synthetic id afterwards redirects to /lobby. Re-load the JSON
   to reseed.
 
-The synthetic-report parity rule (see [`../PLAN.md`](../PLAN.md) §
-Assumptions and Defaults) requires every UI phase that extends
+The synthetic-report parity rule requires every change that extends
 `decodeReport` to also extend the legacy parser in lockstep, or to
 record in the parser's `README.md` that the new field cannot be
 derived from legacy text. This keeps the synthetic-mode coverage in