fix(release): restore automatic updates by shipping the speech engine on demand

Auto-update could not work at all: the installer was 189 MB because it carried
the local speech engine and ffmpeg, and the download feed rejects uploads over
about 100 MiB, so update metadata could never be published.

The installer now leaves those components out and the app fetches them the first
time they are needed, verifying every part and the joined archive before
installing. The installer is 90.6 MiB, the update feed is published again, and
updates stay small because the engine is not re-sent on every release.

The fetch is visible and recoverable: the download runs with progress, a failed
install cleans up after itself, and Settings > STT shows the runtime status with
a manual download action for when the automatic one cannot run.

CHANGELOG.md

@@ -13,6 +13,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Cloud-optional backup (encrypted, opt-in)
 - Plugin system for custom pipelines
 
+## [1.3.2] - 2026-09-18
+
+### Changed
+- **Auto-update works again**: the installer no longer carries the local speech engine
+  and ffmpeg. Bundling them pushed the installer to 189 MB, and the download feed sits
+  behind Cloudflare, which rejects uploads over ~100 MiB with HTTP 413 — so update
+  metadata could not be published at all. The installer is now 90.5 MiB and the update
+  feed is published again.
+- **The app fetches its speech engine and ffmpeg when they are first needed**, verifying
+  every part and the joined archive by SHA-256 before installing them under the app data
+  folder. Updates stay small (the engine is not re-downloaded on every release), and the
+  Settings > STT tab shows the runtime status with a manual download action.
+
 ## [1.3.1] - 2026-09-18
 
 ### Fixed