fix(i18n): comprehensive audit of translated strings across web and native

- Replace hand-rolled pluralization (ternary suffix hacks) with `plural` macro
- Wrap 40+ untranslated user-facing strings with LingUI macros: aria-labels,
  accessibilityLabels/Hints, placeholders, error fallbacks, toast overrides
- Unify episode progress format to `${watched}/${plural(total, ...)}` across
  all 4 call sites (title-card, continue-watching, season-accordion)
- Unify capitalization: "Sign in", "Sign out", "Create account",
  "Change password", "Update password", "Image cache", "Remove from library",
  "Mark Watched", "Trending Today", "On Watchlist", "or"
- Translate cron schedule strings in system health via `i18n._(msg)` with
  locale-aware day names via `Intl.DateTimeFormat`
- Move Zod validation schemas inside components with `useMemo(() => ..., [t])`
  so validation messages are translatable at runtime
- Unify "Watched all of" variable naming to `seasonLabel` across all call
  sites to produce a single msgid
- Remove trailing period from lone "Failed to..." error message
- Add EAS build i18n template extraction step

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/eas-build.yml

@@ -47,6 +47,9 @@ jobs:
       - name: Install dependencies
         run: bun install --frozen-lockfile
 
+      - name: Extract i18n template
+        run: bunx lingui extract-template
+
       - name: Build
         working-directory: apps/native
         run: eas build --platform ${{ inputs.platform || 'all' }} --profile ${{ inputs.profile || 'production' }} --non-interactive --no-wait