docs(player): allocate UR-074/DR-162 for the streaming bitrate cap

The feature shipped tagged against DR-160, which a parallel session had
claimed for picture-in-picture in the meantime. Renumbered to DR-162
across the Rust and frontend TRACES comments (the PiP tags in
VideoPlayer.svelte, pictureInPicture.ts and nativeVideo.ts keep DR-160)
and regenerated bindings.ts.

Adds the requirement rows the tags point at: UR-074 for the user need, and
DR-162 covering why the cap has to reach the PlaybackInfo negotiation and
not only the transcode URL, why the ceiling is process-wide, and why the
Settings default persists while the in-player override does not. Notes
that this gives UR-070 its resume-at-the-same-point mechanism while the
server-offered rendition list that requirement also asks for stays
proposed. UT-156/157 record what the tests pin.

docs/specs/streaming-bitrate-cap.md carries the layer assignment — the
step definitions, the video/audio split, the resolution pairing and the
reload decision are all Rust; the frontend holds a serde token and the
labels it was handed.

TRACES: UR-074 | DR-162 | UT-156, UT-157

src-tauri/src/commands/player/settings.rs

@@ -1,6 +1,6 @@
 //! Audio and video playback settings commands.
 //!
-//! TRACES: UR-022, UR-027, UR-031, UR-032, UR-033, UR-074 | DR-025, DR-030, DR-034, DR-035, DR-036, DR-160, IR-020
+//! TRACES: UR-022, UR-027, UR-031, UR-032, UR-033, UR-074 | DR-025, DR-030, DR-034, DR-035, DR-036, DR-162, IR-020
 
 use std::sync::Arc;
 
@@ -22,7 +22,7 @@ use crate::utils::lock::MutexSafe;
 /// reverts to uncapped on the next launch spends their data allowance without
 /// ever showing them a changed setting.
 ///
-/// TRACES: UR-074 | DR-160
+/// TRACES: UR-074 | DR-162
 const STREAMING_QUALITY_KEY: &str = "streaming_quality";
 
 #[tauri::command]
@@ -82,7 +82,7 @@ pub async fn player_set_video_settings(
 
     // The bandwidth ceiling is read by the repository's URL builders and by the
     // PlaybackInfo negotiation, neither of which can see this wrapper.
-    // TRACES: UR-074 | DR-160
+    // TRACES: UR-074 | DR-162
     crate::repository::online::set_streaming_quality(validated.streaming_quality);
     persist_streaming_quality(&db, validated.streaming_quality).await;
 
@@ -104,7 +104,7 @@ pub async fn player_set_video_settings(
 /// frontend reads them here rather than encoding them — the same arrangement as
 /// [`player_get_eq_presets`].
 ///
-/// TRACES: UR-074 | DR-160
+/// TRACES: UR-074 | DR-162
 #[tauri::command]
 #[specta::specta]
 pub async fn player_get_streaming_qualities(
@@ -119,7 +119,7 @@ pub async fn player_get_streaming_qualities(
 /// setting has already been applied in memory, and refusing the whole call
 /// because the write failed would leave the UI showing a cap that *is* active.
 ///
-/// TRACES: UR-074 | DR-160
+/// TRACES: UR-074 | DR-162
 async fn persist_streaming_quality(db: &State<'_, DatabaseWrapper>, quality: StreamingQuality) {
     let db_service = {
         let database = db.0.lock_safe();
@@ -155,7 +155,7 @@ async fn persist_streaming_quality(db: &State<'_, DatabaseWrapper>, quality: Str
 /// default — uncapped — in place, so a database problem degrades to the old
 /// behaviour rather than to an arbitrary limit.
 ///
-/// TRACES: UR-074 | DR-160
+/// TRACES: UR-074 | DR-162
 pub async fn restore_streaming_quality(app: &tauri::AppHandle) {
     let db_service = {
         let Some(db) = app.try_state::<DatabaseWrapper>() else {