chore(traceability): shift this branch's ids clear of master's

Master allocated DR-224 and UT-211 while this branch was in flight — the third
collision on this work. Everything here moves up by one: DR-224..236 become
DR-225..237, UT-211..213 become UT-212..214. UR-079, UR-080 and IR-033 were
still free and are unchanged.

Mechanical, and matched on each row's own text rather than on its number, so a
row cannot be shifted twice or the wrong one caught. Master's DR-224 (the
background-audio toggle) and UT-211 are untouched.

docs/specs/linux-native-video-spike.md

@@ -295,13 +295,13 @@ anything.
   closed** — hls.js is serving as an HLS demuxer, exactly as (2) above supposed,
   and mpv gives up nothing by replacing it.
 
-  Recorded as DR-228 (Won't Do) rather than deleted, because it is a
+  Recorded as DR-229 (Won't Do) rather than deleted, because it is a
   measurement: a server that *does* publish a ladder would change the answer, and
   the re-negotiation path is the hook that work would build on.
 
   **The direct-play path now exists.** It did not when this spike was written —
   every video play went through the HLS transcode endpoint. Backend-owned stream
-  selection (DR-224 … DR-229) built it: Rust negotiates direct play / direct
+  selection (DR-225 … DR-230) built it: Rust negotiates direct play / direct
   stream / transcode and hands every backend one `StreamSelection` carrying the
   URL, the transport and the chosen rendition. **That is the contract this
   implementation consumes** — mpv is a consumer of a decision already made, not a