docs(backlog): add Phase 8 — platform/DX/showcase (WP-37..46)

New phase from the 5-item analysis: linked showcase snippets + animations,
runnable scaffolding generators (pages/wizards/context/SSP), dependency graph +
declarative boundaries, PII hardening (branded Bsn VO + masked-value atom +
persisted no-PII audit) doubling as a privacy showcase, and Vitest coverage.
Goal: both a teaching showcase and a production starter template. Sequenced with
priorities + dependencies in the README.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/project/backlog/WP-46-vitest-coverage.md

@@ -0,0 +1,34 @@
+# WP-46 — Vitest coverage (report + thresholds)
+
+Status: todo
+Phase: 8 — platform/DX/showcase
+Priority: P1
+
+## Why
+
+Tests run via the `@angular/build:unit-test` (Vitest) builder but report no coverage — there's no
+visibility into what the house test rules actually cover. A template/showcase should surface this.
+
+## Decisions
+
+- **Step 1 — verify wiring:** confirm how coverage is enabled with the Angular unit-test builder
+  (`codeCoverage` option and/or a vitest config), add `@vitest/coverage-v8`.
+- `npm run test:coverage` → text + HTML/lcov report.
+- **Report-only first** (ponytail: visibility before a blocking gate, like the semgrep job).
+  Threshold focus on the layers the house rules already demand tests for (`domain/**`, pure
+  combinators, `parse*` boundaries, reducers), not a blanket global %; exclude stories, the
+  generated `api-client.ts`, and DTOs/contracts.
+- Wire into `ci-local.sh`/CI **non-blocking**, with a documented path to flip on enforcement later.
+- **Open choice:** report-only vs enforce a minimum now.
+
+## Files
+
+- `package.json` (`test:coverage` + dep), coverage config (builder option or vitest config).
+- `scripts/ci-local.sh` / `.github/workflows/ci.yml` — non-blocking coverage step.
+- `.gitignore` — ignore the coverage output dir.
+
+## Acceptance criteria
+
+- [ ] `npm run test:coverage` produces a report (text + HTML/lcov) with sensible excludes.
+- [ ] Coverage runs in CI without failing the build (report-only).
+- [ ] `npm run ci` green.