feat: expand Playwright E2E coverage (#155)

* feat: comprehensive Playwright E2E test rewrite

Rewrite all E2E tests with correct CSS selectors, add new spec files,
and implement robust auth handling to work within backend rate limits.

Changes:
- Rewrite fixtures/index.ts with JWT-based /auth/me mock to avoid
  10 req/min rate limit on /auth/me during test runs
- Rewrite auth.setup.ts with offline JWT validity check to reuse
  existing auth state across runs (saves login rate-limit budget)
- Rewrite auth.spec.ts (6 tests) - login page, fields, submit,
  redirect guard, invalid credentials, login/register toggle
- Rewrite dashboard.spec.ts (8 tests) - header, nav tabs,
  navigation, overview/schedules sections, days selector, redirect
- Rewrite medications.spec.ts (8 tests) - form fields, stock
  inventory, package type toggle, intake schedule, save/cancel,
  unsaved changes guard
- Rewrite settings.spec.ts (12 tests) - language, notification
  matrix, thresholds, calculation mode, toggle switch, export/import,
  user menu navigation
- Create planner.spec.ts (9 tests) - form, date inputs, calculate,
  reset, checkbox, submit, tab state, eyebrow heading
- Create schedule.spec.ts (12 tests) - timeline, days selector,
  past/future toggles, day blocks, today highlight, collapse/expand,
  overview table, share button
- Update playwright.config.ts: remove mobile projects, enable
  webServer section for CI
- Add .github/workflows/e2e.yml CI workflow for Playwright tests

Total: 57 E2E tests across 6 spec files, all passing consistently
across 5+ consecutive runs without backend restart.

Closes #154

* feat: add comprehensive E2E data tests with medication CRUD, dashboard, planner, schedule

Add 48 new Playwright E2E tests covering real medication data scenarios:
- medication-crud: 14 tests for create/edit/delete/list via UI form
- dashboard-data: 13 tests for overview table, timeline, dose tracking
- planner-data: 9 tests for demand calculator with results/status chips
- schedule-data: 11 tests for timeline, collapse/expand, dose mark/undo

Infrastructure improvements:
- Add API helpers (createMedicationViaAPI, deleteMedicationViaAPI,
  deleteAllMedicationsViaAPI) with retry logic for rate-limit resilience
- Configure chromium-data project for serial execution with retry:1
- Add /auth/me mock to avoid rate-limit exhaustion on auth endpoint
- Increase navigateTo reliability with networkidle waits
- Increase auth token validity threshold from 2 to 10 minutes
- Make backend rate limit configurable via RATE_LIMIT_MAX env var
- Set RATE_LIMIT_MAX=300 in dev docker-compose for E2E test support

Total suite: 57 empty-state + 48 data tests = 105 tests (chromium)

* test: add E2E tests for medication editing, stock status, and share schedule

- medication-edit.spec.ts: 10 tests covering generic name, notes,
  taken-by add/remove, expiry date, refill, intake schedule editing,
  adding intake rows, reminder toggle, and package type changes
- stock-status.spec.ts: 12 tests verifying dashboard shows correct
  status chips (High/Normal/Warning/Danger) for different stock levels,
  overview table, reorder card, detail modal, and planner integration
- share-schedule.spec.ts: 10 tests for taken-by badges, share button,
  share dialog, link generation, shared schedule page navigation,
  dose tracking on shared page, and notes display
- fixtures/index.ts: add createShareTokenViaAPI, updateSettingsViaAPI
  helpers; expand createMedicationViaAPI with takenBy, notes, expiryDate
- playwright.config.ts: update testMatch/testIgnore for new test files
- docker-compose.dev.yml: increase RATE_LIMIT_MAX to 1000 for E2E tests

* docs: refine release-manager instructions for CLI safety and commit-linked release notes

* fix: resolve PR155 CI failures for frontend lint and e2e proxy

* fix: stabilize auth-related e2e checks in CI

backend/src/index.ts

@@ -164,7 +164,7 @@ await app.register(sensible);
 await app.register(helmet);
 await app.register(cors, { origin: origins, credentials: true });
 await app.register(rateLimit, {
-	max: 100,
+	max: Number(process.env.RATE_LIMIT_MAX) || 100,
 	timeWindow: "1 minute",
 });
 await app.register(cookie, { secret: env.COOKIE_SECRET ?? "dev-cookie-secret" });