Analytics, self-update and Report a problem

- Anonymous PostHog analytics (ui/frame_telemetry.py): usage on by default
  after a first-run notice; compatibility results and error details opt-in,
  offered together by the notice's "Share more to help fix problems" button.
  Random id, no person profiles or GeoIP, scrubbed text, an offline outbox,
  and "Show what's been sent" in the new Privacy panel. Inert without a
  project key, from a source checkout, or with DO_NOT_TRACK=1.
- APK installs now record install_failed when the APK itself won't install,
  and offer a 20-second test after installing. Opted-in reports reach the
  shared database through PostHog and `frame_compat_db.py sync`.
- The desktop app updates itself from published releases (app/updater.js):
  update.json from releases/latest/download, SHA-256 checked, no downgrades;
  macOS bundle swap, Windows NSIS, Linux AppImage, otherwise the release page.
  scripts/publish-release.sh publishes a tested draft with its manifest.
- Report a problem (header button, Privacy panel, Help menu) files a GitHub
  issue through the website's feedback API, with a previewed, scrubbed
  diagnostics snapshot; activity and logs only when asked for.

Reviewed by GPT-6 Astra (xhigh, read-only) three times; all findings fixed.
Docs: docs/privacy.md, docs/releasing.md.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

README.md

@@ -104,6 +104,10 @@ already ships (sideloading a game copies Valve's own devkit scripts to
 | **Linux** (arm64) | [AppImage](https://github.com/saphid/steam-frame/releases/latest/download/Frame-Control-linux-arm64.AppImage) · [.deb](https://github.com/saphid/steam-frame/releases/latest/download/Frame-Control-linux-arm64.deb) | `ssh`, and `adb` for Android apps (`sudo apt install adb`) |
 
 The app brings its own Python and `adb`; SSH is built into macOS and Windows.
+From 0.4 it updates itself: when a new version is published, a banner offers
+**Update and restart**. It sends anonymous usage statistics, which you can turn
+off. Sharing compatibility results and error details is opt-in. See
+[docs/privacy.md](docs/privacy.md).
 Google doesn't publish `adb` for arm64 Linux, so that build uses your
 distribution's. If you already have `adb`, the app uses yours.
 
@@ -172,9 +176,11 @@ entry to `~/.ssh/config` and keys at `~/.ssh/id_ed25519_frame` and
 ## Feedback
 
 This is a first public test, so reports are really useful, especially from
-Windows and Linux. The quickest way is the
-[feedback form](https://frame-control.pages.dev/feedback/): no GitHub account
-needed, and it opens an issue here. Please include:
+Windows and Linux. The quickest way is **Report a problem** in the app (the
+warning-sign button at the top, or **Help → Report a Problem…**). It adds
+diagnostics with personal details removed, shows you exactly what's included,
+and opens an issue here. You don't need a GitHub account. Without the app,
+use the [feedback form](https://frame-control.pages.dev/feedback/). Please include:
 
 - what you tried and what happened
 - your computer's OS and your SteamOS build (Steam Settings → System)
@@ -230,7 +236,8 @@ cd app && npm install && npm start      # run the app from the checkout
 
 The server is Python stdlib only; the app is Electron. GitHub Actions runs the
 tests on macOS, Windows and Linux, and a `v*` tag builds all three installers
-into the release. See [building](docs/frame-control.md#building).
+into a draft release, which reaches users once published. See
+[building](docs/frame-control.md#building) and [releasing](docs/releasing.md).
 
 ## License