feat(downloads): redesign download manager (#1313)

* docs(downloads): specify manager MVP redesign

* docs(downloads): plan manager MVP implementation

* docs(downloads): tighten manager validation plan

* fix(downloads): keep renderer download state global

* fix(downloads): make active count accessible

* feat(downloads): derive queue and library view model

* test(downloads): close view model coverage gaps

* fix(downloads): stabilize malformed view model data

* refactor(downloads): isolate library navigation

* fix(downloads): report library navigation failures

* feat(downloads): add ready-to-watch library

* feat(downloads): add active download queue

* feat(downloads): finish manager MVP

* docs(downloads): clarify detail-first offline behavior

* docs(downloads): plan detail navigation follow-up

* fix(downloads): open completed movies in details

* test(downloads): cover pending series navigation

* fix(downloads): honor the global cover size

* fix(downloads): prefer local playback in shared details

* fix(downloads): preserve external launch priority

* fix(downloads): prefer local playback in Xtream details

* test(downloads): cover offline detail journey

* docs(downloads): document offline detail behavior

* docs(downloads): format detail navigation plan

* fix(downloads): open Stalker items in provider details

* docs(downloads): clarify Stalker navigation fallback

* fix(xtream): isolate reused detail identities

* fix(xtream): ignore stale VOD positions

* fix(downloads): keep offline Xtream playback available

* docs(downloads): clarify provider playback availability

* docs(downloads): design missing-file recovery

* docs(downloads): plan missing-file recovery

* feat(downloads): derive completed file availability

* feat(downloads): recover missing completed files

* feat(downloads): refresh missing local files

* feat(downloads): separate missing files from ready media

* feat(downloads): surface missing files for recovery

* refactor(downloads): simplify ready cards

* test(downloads): cover missing-file and series journeys

* feat(downloads): finish missing-file recovery

* docs(downloads): design offline detail views

* docs(downloads): plan offline detail views

* feat(downloads): persist offline metadata snapshots

* fix(downloads): complete metadata snapshot bridge contract

* feat(downloads): manage offline metadata snapshots

* fix(downloads): harden metadata snapshot updates

* fix(downloads): restrict snapshot artwork

* fix(downloads): guard restart artwork URL

* fix(downloads): refine artwork URL checks

* feat(downloads): expose offline metadata updates

* fix(downloads): keep metadata service change focused

* fix(downloads): preserve metadata error conventions

* feat(downloads): derive offline detail content

* fix(downloads): preserve unknown episode coordinates

* feat(downloads): add focused offline detail routes

* fix(downloads): ignore fragments in shell route state

* fix(downloads): normalize fragments before queries

* feat(downloads): open ready cards in offline details

* fix(downloads): use native disabled card styles

* feat(downloads): enrich offline detail metadata

* fix(downloads): harden offline metadata resolution

* fix(downloads): preserve stalker provider titles

* fix(downloads): distinguish stalker metadata seeds

* fix(downloads): stabilize offline metadata refresh

* fix(downloads): throttle sparse metadata refreshes

* fix(downloads): type metadata language settings

* feat(downloads): render offline movie and series details

* fix(downloads): harden offline detail interactions

* fix(downloads): close offline detail edge cases

* feat(downloads): hand off to provider-only details

* fix(downloads): preserve stalker provider handoff

* feat(downloads): capture metadata at download time

* fix(downloads): preserve snapshot source semantics

* fix(downloads): preserve episode snapshot identity

* docs(downloads): document offline details flow

* docs(downloads): clarify stalker provider fallback

* test(downloads): cover offline detail journeys

* test(downloads): stabilize offline detail selectors

* style(downloads): format changed files

* docs(downloads): clean design spec formatting

* fix(downloads): preserve offline library ownership

* test(downloads): fix Windows workspace navigation

* test(database): preserve Electron tsconfig resolution

* perf(downloads): avoid blocking file availability probes

docs/architecture/sqlite-db-worker.md

@@ -245,11 +245,13 @@ counts only content and category deletion candidates; favorite,
 recently-viewed, and hidden-category user data is timed but is not added to
 that count. The matching write count uses the same deletion-candidate
 definition. Playlist-delete collection counts every collected favorite,
-recently-viewed, playback-position, download, content, and category ID. Its
-write count adds the final playlist row. Both write spans include every
-existing cooperative checkpoint, 100-row transaction, progress callback, and,
-for playlist deletion, the final playlist-row autocommit; they are not exact
-SQLite commit-time measurements.
+recently-viewed, playback-position, content, and category ID. Download rows are
+intentionally excluded: they own local offline files independently of the
+source playlist and survive source deletion, with provider handoff disabled
+while that source is absent. The write count adds the final playlist row. Both
+write spans include every existing cooperative checkpoint, 100-row
+transaction, progress callback, and, for playlist deletion, the final
+playlist-row autocommit; they are not exact SQLite commit-time measurements.
 
 Successful end markers carry only row/item counts. Error or cancellation still
 closes the active phase without metadata and preserves the original error.