feat(xtream): resume the latest series episode (#1187)

Dashboard Continue Watching now carries the exact saved season/episode into
Xtream series details and starts it at the persisted offset. Successful
external MPV/VLC launches persist the launched episode and retarget the
series CTA to "Play episode N". Recent-history rows keyed by an episode id
resolve their parent series before navigation.

Includes maintainer follow-ups: no zero-offset resume on failed position
loads, seriesXtreamId-gated resume targets for legacy rows, and patch
coverage raised from 76.7% to 93.9%.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/web/jest.config.ts

@@ -39,6 +39,7 @@ export default {
     tslib: 'tslib/tslib.es6.js',
     '^iptv-playlist-parser$':
       '<rootDir>/src/test-stubs/iptv-playlist-parser.mjs',
+    '^video.js$': '<rootDir>/src/test-stubs/video-js.js',
     '^rxjs': '<rootDir>/../../node_modules/rxjs/dist/bundles/rxjs.umd.js',
     '^uuid$': '<rootDir>/../../node_modules/uuid/wrapper.mjs',
   },