chore(release): 0.69.0 — E3 backend architecture consolidation

Bump VERSION + user-facing release notes for the E3 epic (Plex god-module split,
downloads owner-unification, backend contract & conventions). Observable wins:
Plex catalog prune, download reliability (no false stalls, fair queue, no
file-delete-under-live-download). 20 commits, four clean /code-review high rounds.

VERSION

@@ -1 +1 @@
-0.68.0
+0.69.0

frontend/src/lib/releaseNotes.ts

@@ -14,6 +14,19 @@ export interface ReleaseEntry {
 }
 
 export const RELEASE_NOTES: ReleaseEntry[] = [
+  {
+    version: "0.69.0",
+    date: "2026-08-19",
+    summary:
+      "Mostly under-the-hood consolidation of the backend, with a few reliability wins you'll notice in Plex and downloads.",
+    fixes: [
+      "Movies and shows removed from Plex now disappear from your library on the next sync, instead of lingering and failing to play. A safety guard skips the cleanup whenever Plex returns an incomplete listing, so a temporary hiccup can never wipe a library.",
+      "Downloads are more reliable: a slow re-encode is no longer mistaken for a stalled download and stopped; queuing a second copy of the same video while the first is still downloading no longer blocks the queue behind it; and canceling or deleting a download can no longer remove a file another download still shares, even when several run at once.",
+    ],
+    chores: [
+      "A large internal refactor with no behavior change: the Plex browse and download-worker god-modules were split into focused modules, download state transitions and file bookkeeping were centralized, five unused endpoints were removed, admin config settings were unified into one store, and the request contracts and module docs were tidied — all under new automated tests and four clean code-review passes.",
+    ],
+  },
   {
     version: "0.68.0",
     date: "2026-08-18",