feat(downloads): queue season episode downloads (#1357)

* docs(downloads): specify season queueing

* docs(downloads): plan season queue implementation

* feat(downloads): define episode queue identity

* fix(downloads): align episode identity contract

* feat(downloads): coordinate season queue submissions

* fix(downloads): keep queue coordination provider neutral

* fix(downloads): reconcile legacy episode identities

* fix(downloads): fail closed on invalid stored coordinates

* refactor(downloads): adapt Xtream episode requests

* fix(downloads): use canonical Stalker episode ids

* test(downloads): cover Stalker adapter reactivity

* feat(downloads): add selected season queue action

* refactor(downloads): extract season download presenter

* feat(downloads): localize season queue feedback

* test(downloads): cover series batch queue flow

* test(downloads): harden series queue fixtures

* docs(downloads): describe season queueing

* docs(downloads): clarify season queue IPC contract

* fix(downloads): isolate season header build warnings

* fix(downloads): label season view toggles

* fix(downloads): preserve Xtream episode headers

* fix(downloads): fail closed on stale episode state

* fix(downloads): align renderer queue safeguards

* fix(downloads): block ambiguous episode actions

* fix(downloads): accept nullable legacy coordinates

* fix(downloads): preserve scoped episode ownership

* fix(downloads): probe restored files asynchronously

* fix(downloads): bound restored file probes

* fix(downloads): release timed out file probes

* fix(downloads): bound file probe callers

* fix(downloads): refresh stable season skips

* fix(downloads): fail closed before provider prep

* fix(downloads): preserve retained partial ownership

* fix(downloads): reconcile partial cleanup completion

* fix(downloads): await authoritative list refresh

* fix(downloads): coalesce list refreshes

* fix(downloads): preserve specials season identity

* fix(stalker): preserve specials season mapping

* fix(downloads): distinguish missing Xtream seasons

libs/shared/interfaces/src/lib/electron-api.interface.ts

@@ -138,6 +138,23 @@ export const ELECTRON_BRIDGE_DOWNLOAD_STATUSES = {
 export type ElectronBridgeDownloadStatus =
     (typeof ELECTRON_BRIDGE_DOWNLOAD_STATUSES)[keyof typeof ELECTRON_BRIDGE_DOWNLOAD_STATUSES];
 
+export const ELECTRON_BRIDGE_DOWNLOAD_START_REASONS = {
+    AlreadyDownloaded: 'already-downloaded',
+    AlreadyInProgress: 'already-in-progress',
+} as const;
+
+export type ElectronBridgeDownloadStartReason =
+    (typeof ELECTRON_BRIDGE_DOWNLOAD_START_REASONS)[keyof typeof ELECTRON_BRIDGE_DOWNLOAD_START_REASONS];
+
+export const ELECTRON_BRIDGE_EPISODE_IDENTITY_SCOPES = {
+    StalkerEmbeddedVod: 'stalker-embedded-vod',
+    StalkerLazyVod: 'stalker-lazy-vod',
+    StalkerRegularSeries: 'stalker-regular-series',
+} as const;
+
+export type ElectronBridgeEpisodeIdentityScope =
+    (typeof ELECTRON_BRIDGE_EPISODE_IDENTITY_SCOPES)[keyof typeof ELECTRON_BRIDGE_EPISODE_IDENTITY_SCOPES];
+
 export type ElectronDownloadFileAvailability =
     'available' | 'missing' | 'not-applicable';
 
@@ -534,6 +551,7 @@ export interface ElectronBridgeDownloadStartPayload {
     seriesXtreamId?: number;
     seasonNumber?: number;
     episodeNumber?: number;
+    episodeIdentityScope?: ElectronBridgeEpisodeIdentityScope;
     playlistName?: string;
     playlistType?: ElectronBridgePlaylistType;
     serverUrl?: string;
@@ -543,6 +561,7 @@ export interface ElectronBridgeDownloadStartPayload {
 
 export interface ElectronBridgeDownloadStartResult extends ElectronBridgeErrorResult {
     id?: number;
+    reason?: ElectronBridgeDownloadStartReason;
 }
 
 export interface ElectronBridgeDownloadRedownloadResult extends ElectronBridgeErrorResult {
@@ -557,6 +576,7 @@ export interface ElectronDownloadItem {
     seriesXtreamId?: number;
     seasonNumber?: number;
     episodeNumber?: number;
+    episodeIdentityScope?: ElectronBridgeEpisodeIdentityScope | null;
     title: string;
     url: string;
     fileName?: string;