domain: player/reporting ticks -> milliseconds (phase 4c)

Playback position now crosses the IPC boundary in milliseconds. Ticks
survive only inside Rust (DB storage, Jellyfin API) and at the genuine
remote-session boundary (session seek / transfer / RemoteControls).

Rust command signatures (ms in, converted to ticks internally):
- storage_update_playback_progress / _context: position_ms
- repository_report_playback_start / _progress / _stopped: position_ms
- PlaybackProgress.position_ticks -> position_ms (converted in the query)

Frontend:
- playbackReporting, playerEvents, VideoPlayer, Queue, player/[id] resume:
  seconds*1000 / durationMs/1000 instead of tick math.
- repository-client + syncService param names -> positionMs.
- Tests updated to ms fixtures/assertions.

Out of scope (legitimately ticks): NowPlayingItem, PlayState.positionTicks,
sessionSeek, playbackModeTransferToLocal, RemoteControls, SessionCard — the
remote Jellyfin session API.

Rust 456, frontend 644, check clean.

src/lib/api/bindings.ts

@@ -670,15 +670,15 @@ async storageDeleteUser(userId: string) : Promise<null> {
  * Update playback progress in local database
  * This stores the progress locally for offline access and "continue watching"
  */
-async storageUpdatePlaybackProgress(userId: string, itemId: string, positionTicks: number) : Promise<null> {
-    return await TAURI_INVOKE("storage_update_playback_progress", { userId, itemId, positionTicks });
+async storageUpdatePlaybackProgress(userId: string, itemId: string, positionMs: number) : Promise<null> {
+    return await TAURI_INVOKE("storage_update_playback_progress", { userId, itemId, positionMs });
 },
 /**
  * Update playback progress with context in local database
  * This stores the progress along with playback context (container vs single)
  */
-async storageUpdatePlaybackContext(userId: string, itemId: string, positionTicks: number, contextType: string | null, contextId: string | null) : Promise<null> {
-    return await TAURI_INVOKE("storage_update_playback_context", { userId, itemId, positionTicks, contextType, contextId });
+async storageUpdatePlaybackContext(userId: string, itemId: string, positionMs: number, contextType: string | null, contextId: string | null) : Promise<null> {
+    return await TAURI_INVOKE("storage_update_playback_context", { userId, itemId, positionMs, contextType, contextId });
 },
 /**
  * Mark item as played in local database
@@ -1332,20 +1332,20 @@ async repositoryOpenLiveStream(handle: string, itemId: string) : Promise<LiveStr
 /**
  * Report playback start
  */
-async repositoryReportPlaybackStart(handle: string, itemId: string, positionTicks: number) : Promise<null> {
-    return await TAURI_INVOKE("repository_report_playback_start", { handle, itemId, positionTicks });
+async repositoryReportPlaybackStart(handle: string, itemId: string, positionMs: number) : Promise<null> {
+    return await TAURI_INVOKE("repository_report_playback_start", { handle, itemId, positionMs });
 },
 /**
  * Report playback progress
  */
-async repositoryReportPlaybackProgress(handle: string, itemId: string, positionTicks: number) : Promise<null> {
-    return await TAURI_INVOKE("repository_report_playback_progress", { handle, itemId, positionTicks });
+async repositoryReportPlaybackProgress(handle: string, itemId: string, positionMs: number) : Promise<null> {
+    return await TAURI_INVOKE("repository_report_playback_progress", { handle, itemId, positionMs });
 },
 /**
  * Report playback stopped
  */
-async repositoryReportPlaybackStopped(handle: string, itemId: string, positionTicks: number) : Promise<null> {
-    return await TAURI_INVOKE("repository_report_playback_stopped", { handle, itemId, positionTicks });
+async repositoryReportPlaybackStopped(handle: string, itemId: string, positionMs: number) : Promise<null> {
+    return await TAURI_INVOKE("repository_report_playback_stopped", { handle, itemId, positionMs });
 },
 /**
  * Get image URL for an item
@@ -2070,7 +2070,12 @@ export type PlaybackMode = { type: "local" } | { type: "remote"; session_id: str
 /**
  * Playback progress info
  */
-export type PlaybackProgress = { itemId: string; positionTicks: number; isPlayed: boolean; isFavorite: boolean; playCount: number }
+export type PlaybackProgress = { itemId: string; 
+/**
+ * Resume position in milliseconds. Stored as Jellyfin ticks in the DB;
+ * converted here so the frontend never sees ticks.
+ */
+positionMs: number; isPlayed: boolean; isFavorite: boolean; playCount: number }
 /**
  * Represents a media item that can be played
  *