refactor: refactor date handling across components to use date-fns and Intl.DateTimeFormat

- Replaced moment.js usage with Intl.DateTimeFormat for date formatting in various components.
- Introduced utility functions `normalizeDateLocale` and `formatWithIntl` for locale normalization and date formatting.
- Updated PlaylistSwitcher, RecentPlaylists, ContentCard, EPG components, and MultiEpgContainer to utilize the new date formatting approach.
- Removed moment-date pipe and related tests, simplifying date handling logic.
- Ensured all date displays respect the current locale settings.

Entire-Checkpoint: 271bd0162027

docs/architecture/date-handling.md

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+# Date Handling
+
+## Rules
+
+- Use native `Date`, ISO strings, and epoch timestamps as the stored/runtime values.
+- Use `date-fns` for parsing, arithmetic, and normalization logic.
+- Use Angular `DatePipe` in templates when the value is already a `Date`, ISO string, or epoch timestamp.
+- Use cached `Intl.DateTimeFormat` helpers in TypeScript-only formatting paths where Angular pipes are not available.
+- Do not add new `moment` usage. The app no longer depends on it.
+
+## Locale Strategy
+
+- Date display should follow the user-selected app language from `TranslateService`.
+- When a template renders localized month or weekday names, pass the normalized app locale explicitly to `DatePipe`.
+- Angular locale data is registered in [apps/web/src/app/app-date-locales.ts](/Users/4gray/Code/iptvnator/apps/web/src/app/app-date-locales.ts).
+- App language aliases are normalized in [libs/ui/pipes/src/lib/date-format.util.ts](/Users/4gray/Code/iptvnator/libs/ui/pipes/src/lib/date-format.util.ts):
+  - `ary` -> `ar-MA`
+  - `by` -> `be`
+  - `zhtw` -> `zh-Hant`
+
+## Parsing Boundaries
+
+- Normalize provider-specific or legacy date strings to ISO as early as possible.
+- Keep optional epoch fields such as `startTimestamp` and `stopTimestamp` when the provider already supplies them.
+- Avoid new non-standard `Date.parse(...)` usage for provider formats; prefer explicit `date-fns` parsing when the input is not ISO.