fix(stalker): align season markers and preserve episode loading (#1545)

CLAUDE.md

@@ -1424,7 +1424,7 @@ stream_id`); it drops `series_id`/`movie_id`, so the builder pins the
 - Watch state derives from `inlinePlayback() !== null` only; external MPV/VLC playback keeps the browse layout. Esc and "Close player" exit to browse without navigation; the now-playing back arrow is route-level back (straight to the list via the host's `goBack()`)
 - Xtream VOD treats metadata presentation and playability as separate contracts. Empty or sparse `get_vod_info` data keeps the curated fallback detail page, while Play/Resume, Favorite, and Download remain available whenever a positive stream id and non-empty container extension resolve from `movie_data` or the catalog fields. Playback fields are selected as one atomic pair in detail → recovered catalog → owner-valid cached catalog order; incomplete candidates never combine into a synthetic source. In-memory VOD categories/streams carry their owner playlist, and cross-portal Favorites/Recent details ignore arrays from another playlist so colliding Xtream ids cannot inject stale playback or presentation data. When Electron's normalized catalog cache lacks the extension, the detail loader immediately publishes the sparse fallback and ends its loading state, then performs a best-effort category-scoped raw catalog lookup and reactively upgrades the same item with actions on success. It maps the normal SQLite route category through all persisted categories, including hidden ones, while also accepting the provider `xtream_id` carried by cross-portal Similar links; ambiguous numeric matches keep local-id precedence, deduplicate provider candidates, and try the next candidate when the exact VOD is absent. PWA falls back to API categories. It skips that request when existing data is sufficient, never sends an unresolved database id as a provider id, preserves concurrent metadata enrichment, and drops late detail/recovery responses after replacement, playlist reset, or detail teardown. Inline playback moves either detail page into Watch; external MPV/VLC remains in Browse. Unresolvable items expose no actions, and playback/download titles and posters fall back through `info`, `movie_data`, then catalog fields.
 - A successful external MPV/VLC episode launch immediately persists the selected episode as the latest playback-position entry and retargets the series CTA to `Play episode N`; real player telemetry overwrites that marker when available, so episode identity is reliable while exact external timestamps remain best-effort.
-- Stalker preserves this contract for regular `/series`, embedded VOD `series[]`, and lazy Ministra VOD `is_series` items; `is_series` is normalized only from `true`, `1`, or `'1'`. Quick-start translation parameters must reach the CTA, and inline/external episode handoffs must include the parent series id plus resolved season and episode numbers. Lazy VOD episode tracking IDs scope the parent series, provider episode, season key, and episode number; the previous season/episode hash is only a compatibility alias. Exact scoped positions win, while compatible legacy rows are considered only for the current parent and must match any stored season/episode coordinates. The scoped row is persisted through the strict failure-propagating boundary before confirmed legacy cleanup, so a failed save keeps the old row; compatibility is lazy and performs no schema migration or bulk rewrite.
+- Stalker preserves this contract for regular `/series`, embedded VOD `series[]`, and lazy Ministra VOD `is_series` items; `is_series` is normalized only from `true`, `1`, or `'1'`. Quick-start translation parameters must reach the CTA, and inline/external episode handoffs must include the parent series id plus resolved season and episode numbers. Single-season title markers correct both displayed and playback season coordinates; lazy VOD retains the original provider season key/number for stable IDs and old progress. Lazy VOD episode tracking IDs scope the parent series, provider episode, original season key, and episode number; the previous season/episode hash is only a compatibility alias. Exact scoped positions win, while compatible legacy rows are considered only for the current parent and must match the episode and either its resolved or retained original provider season. The scoped row is persisted through the strict failure-propagating boundary before confirmed legacy cleanup, so a failed save keeps the old row; compatibility is lazy and performs no schema migration or bulk rewrite. Season resources ignore metadata-only selection patches, and episode responses belong to the exact loading VM so navigation cannot mix episode lists.
 - Hosts pass hero chips/meta/actions as `*appDetailTags`/`*appDetailMeta`/`*appDetailActions` templates; the shell stamps them into both the hero and the About block
 - Seasons are tabs (`SeasonTabsComponent`, dropdown beyond 6 seasons) with auto-selection (playing episode's season → resume season → earliest season with unwatched episodes → latest non-empty season; Stalker lazy-VOD series with unhydrated seasons fall back to the first season, and a session's own watched-toggle echo never re-resolves the selection) that fires the same `seasonSelected` lazy-load/enrichment hooks as manual clicks; grid/list episode view toggle persists to localStorage; season descriptions come from `get_series_info` (Xtream, provider-first with URL-only junk filtered by `sanitizeProviderOverview` and a TMDB season-overview fallback stored as `tmdb_season_overviews` by the lazy season enrichment) or TMDB (Stalker)
 - The season header hosts a bulk watched toggle next to "Download season" (both portals): marking writes full-progress position rows for the unwatched episodes only — skipping the episode currently playing/launching, whose position ticks would overwrite the row — and a fully watched season flips the action to unwatch-all (`buildSeasonWatchToggleRequest` in `libs/ui/components/.../season-watch-toggle.util.ts`). Xtream persists via the batch IPC `DB_SAVE/CLEAR_PLAYBACK_POSITIONS_BATCH` (one SQLite transaction; the PWA data source rewrites its localStorage blob once) and refreshes `XtreamStore.loadAllPositions` after any toggle so catalog progress badges follow; Stalker loops the serialized position-mutation queue (legacy-row reconciliation, one coalesced reload) and reports direction-specific partial failures. A batch resolving after navigation neither mutates the new page's state nor shows its snackbar. A series-level counterpart sits in a `⋮` menu at the end of the header row (`SeasonWatchPresenter` owns both scopes' state math; `buildSeriesWatchToggleRequest` flattens every loaded season; the direction is always the one the label advertised). It reuses the same host machinery per portal (Xtream: scope-parameterized `SerialDetailsSeasonWatchService`; Stalker: shared `runWatchToggleBatch` core). Stalker lazy-VOD hydrates unloaded seasons sequentially first (abort with zero writes on a failed fetch; a well-formed EMPTY portal answer marks the season loaded-and-empty via `VodSeriesSeasonVm.episodesLoaded` rather than eternally pending, while `fetchVodSeriesEpisodes` rejects malformed envelopes and answers without recognizable episodes; `loadEpisodesForSeason` is single-flight per season so concurrent callers join one request), re-runs the position reconcile synchronously so hydrated episodes' legacy rows are cleaned, then rebuilds the request keeping the clicked direction — the `hasUnloadedSeasons` container input blocks the unwatch verdict and the count label until everything is loaded. Contract: `docs/architecture/embedded-inline-playback.md`