fix(downloads): block ambiguous episode actions

docs/architecture/download-manager.md

@@ -80,17 +80,19 @@ variants, contextual buttons, and theme-aware styling.
   The exact `(playlistId, contentType, xtreamId)` identity is authoritative.
   Complete `(playlistId, seriesXtreamId, seasonNumber, episodeNumber)`
   coordinates are a legacy episode-compatibility fallback; ambiguous or
-  conflicting matches fail closed, while restarting an eligible legacy row
-  migrates it to the canonical id. Renderer-pending, queued, downloading, and
-  paused episodes are skipped, as are completed rows whose file is available
-  or whose availability is still unknown. Failed, canceled, completed-missing,
-  and row-less episodes are eligible; a completed-missing row is restarted as
-  a fresh download. `DOWNLOADS_START` remains the only start IPC and may return
-  the stable `reason: 'already-in-progress'` for an active match, which the
-  coordinator counts as skipped. There is no batch IPC, schema migration,
-  parallel transfer, or queue reordering: destination authorization, persisted
-  header handling, and the backend's one-active-transfer FIFO semantics remain
-  unchanged.
+  conflicting matches resolve to an explicit renderer conflict state rather
+  than masquerading as a missing row. Both the episode action and season count
+  fail closed for that state, while restarting an eligible legacy row migrates
+  it to the canonical id. Renderer-pending, queued, downloading, and paused
+  episodes are skipped, as are completed rows whose file is available or whose
+  availability is still unknown. Failed, canceled, completed-missing, and
+  unambiguous row-less episodes are eligible; a completed-missing row is
+  restarted as a fresh download. `DOWNLOADS_START` remains the only start IPC
+  and may return the stable `reason: 'already-in-progress'` for an active match,
+  which the coordinator counts as skipped. There is no batch IPC, schema
+  migration, parallel transfer, or queue reordering: destination authorization,
+  persisted header handling, and the backend's one-active-transfer FIFO
+  semantics remain unchanged.
 - **Pure manager model**
   (`download-manager.viewmodel.ts` and `download-library.viewmodel.ts`)
   derives the current route scope, search/category filtering, queue partitions,