release: 0.78.4 — fix Plex transcode playback stall/rebuffer

hls.js startPosition:0 so the transcode/remux HLS session starts VOD-style
at the requested position instead of chasing the live edge of the growing
EVENT playlist.

VERSION

@@ -1 +1 @@
-0.78.3
+0.78.4

frontend/src/lib/releaseNotes.ts

@@ -14,6 +14,18 @@ export interface ReleaseEntry {
 }
 
 export const RELEASE_NOTES: ReleaseEntry[] = [
+  {
+    version: "0.78.4",
+    date: "2026-08-30",
+    summary:
+      "A fix for stuttering and stalling when the Plex player transcodes a video — playback now starts cleanly and keeps a healthy buffer, whether you play from the start or resume/seek partway through.",
+    fixes: [
+      "A transcoded Plex video (any format your browser can't play natively) no longer rebuffers every second, and resuming or seeking into one no longer leaves it stuck on “Loading…” forever. The player now starts the stream at the position you asked for and buffers ahead, instead of chasing the live edge of an in-progress transcode.",
+    ],
+    chores: [
+      "The player builds its HLS client to start at the requested position (the transcode session already begins encoding there), which fixes both the every-second rebuffer and the resume/seek stall in one change. Verified against the HLS library's live-vs-VOD start logic and put through a multi-agent deep-review (correctness, player behaviour, test coverage) that came back clean.",
+    ],
+  },
   {
     version: "0.78.3",
     date: "2026-08-30",