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/settings.rs

@@ -161,7 +161,7 @@ impl AudioSettings {
 /// bitrate so the encoder does not spend a small budget on pixels it cannot
 /// afford. See docs/specs/streaming-bitrate-cap.md.
 ///
-/// TRACES: UR-074 | DR-160
+/// TRACES: UR-074 | DR-162
 #[derive(specta::Type, Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
 #[serde(rename_all = "camelCase")]
 pub enum StreamingQuality {
@@ -296,7 +296,7 @@ pub struct VideoSettings {
     /// `#[serde(default)]` so settings JSON persisted before this field existed
     /// loads as the previous behaviour (uncapped).
     ///
-    /// TRACES: UR-074 | DR-160
+    /// TRACES: UR-074 | DR-162
     #[serde(default)]
     pub streaming_quality: StreamingQuality,
 }
@@ -601,7 +601,7 @@ mod tests {
     /// exceed, so video + audio must fit inside the total — a video bitrate set
     /// to the full cap would overshoot it by the size of the audio track.
     ///
-    /// TRACES: UR-074 | DR-160 | UT-157
+    /// TRACES: UR-074 | DR-162 | UT-157
     #[test]
     fn test_streaming_quality_budget_is_internally_consistent() {
         for quality in StreamingQuality::ALL {
@@ -637,7 +637,7 @@ mod tests {
     /// must fall with it — a lower bitrate paired with a higher resolution would
     /// spend the smaller budget on more pixels, which is backwards.
     ///
-    /// TRACES: UR-074 | DR-160 | UT-157
+    /// TRACES: UR-074 | DR-162 | UT-157
     #[test]
     fn test_streaming_quality_ladder_descends() {
         let steps = StreamingQuality::ALL;
@@ -664,7 +664,7 @@ mod tests {
     /// The persisted form is the serde token, and it must survive a round trip —
     /// a rename here silently resets everyone's saved cap to uncapped.
     ///
-    /// TRACES: UR-074 | DR-160 | UT-157
+    /// TRACES: UR-074 | DR-162 | UT-157
     #[test]
     fn test_streaming_quality_round_trips_through_json() {
         for quality in StreamingQuality::ALL {