perf: remux indexed Cast video at keyframe boundaries

TODO.md

@@ -1,9 +1,16 @@
+- [ ] fix the readme:
+    - clear out redundant and irrelevant overly detailed crap from the readme.
+    - we don't need every minute detail (already described perfectly by the code btw) described in painstakingly verbose paragraphs in the readme.
+    - implementation details are not appropriate in a readme file (without a very good reason to be there).
+    - the readme should be compressed to actually useful information - nothing more - and verbose, irrelevant, or redundant information deleted.
 - [ ] evaluate playback optimization opportunities for YouTube and Miruro — measure benefits before changing behavior
 	- [x] coalesce superseded, not-yet-started seeks in the player and Cast controls; preserve accumulated relative skips and play/pause ordering
-	- [ ] expand Cast H.264/AAC remux coverage with keyframe-aligned segments; preserve seek accuracy, timestamps and receiver compatibility
+	- [x] expand Cast H.264/AAC remux coverage with keyframe-aligned segments; preserve seek accuracy, timestamps and receiver compatibility
 	- [ ] reuse decoder/encoder state during sequential Cast playback; reset on random seeks and preserve independent keyframes and AAC continuity
 	- [ ] evaluate VideoToolbox hardware video decoding for native and Cast playback; retain software fallback for unsupported formats
 	- [ ] benchmark cold start, cached/uncached seeks and sustained playback separately to prioritize the actual bottlenecks
 	- do not enable Miruro HTTP persistence without preserving origin/header checks, or increase caches/shorten Cast segments without measuring the memory/request/codec tradeoffs
+- [ ] add playlist support
+    - maybe by allowing multiple file selection? 🤔
 - [ ] in the "choose what to play" screen, we should change the youtube button to general streaming
 	- we can figure out the stream and how to handle it from the url (i.e. if youtube url, handle as youtube stream; if miruro url, handle accordingly)