feat(playback): recommend recovery actions (#1374)

* docs(playback): design recovery recommendations

* docs(playback): plan recovery recommendations

* refactor(playback): extract diagnostic utilities

* feat(playback): define recovery recommendation contracts

* feat(playback): rank recovery recommendations

* feat(playback): track session recovery attempts

* feat(playback): identify content recovery sessions

* feat(ui): add ranked playback diagnostic panel

* feat(playback): switch temporarily to recommended players

* test(playback): cover temporary player recommendation

* test(playback): verify recommendation capability guards

* docs(playback): document recovery recommendations

* fix(playback): keep recovery keys credential-free

* fix(playback): remove derived tracking ownership

* fix(playback): preserve distinct recovery fallbacks

* fix(playback): reset resume for new sources

* fix(playback): preserve desktop recovery guidance

* docs(playback): clarify recovery policy exceptions

* fix(playback): reject stale progress updates

* fix(playback): keep protected recovery guidance neutral

* test(playback): cover stale progress output

* fix(playback): neutralize protected diagnostic copy

* fix(playback): harden runtime guidance ownership

* fix(playback): stabilize recovery application ownership

* fix(ci): classify playback util coverage

* fix(e2e): preserve playback fixture bytes

apps/web-e2e/src/fixtures/playback/corrupt.ts

@@ -0,0 +1 @@
+This is intentionally not an MPEG transport stream segment.

apps/web-e2e/src/fixtures/playback/fatal-media.m3u8

@@ -0,0 +1,7 @@
+#EXTM3U
+#EXT-X-VERSION:3
+#EXT-X-TARGETDURATION:1
+#EXT-X-MEDIA-SEQUENCE:0
+#EXTINF:1,
+corrupt.ts
+#EXT-X-ENDLIST

apps/web-e2e/src/fixtures/playback/unsupported.mkv

@@ -0,0 +1 @@
+This fixture intentionally declares Matroska without playable media bytes.