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>

compat-db/README.md

@@ -1,9 +1,32 @@
 # compat-db: Frame Control's compatibility database
 
 A private [Lakebed](https://docs.lakebed.dev/) capsule holding compatibility
-reports for Android apps on the Steam Frame. For now only the maintainer's
-copy of Frame Control has the key to read or write it. Everyone else's reports
-stay on their own Mac (see `shared()` in `ui/frame_compat_db.py`).
+reports for Android apps on the Steam Frame. Only the maintainer's copy of
+Frame Control has the key to read or write it (see `shared()` in
+`ui/frame_compat_db.py`). Everyone else's reports stay on their computer
+unless they turn on **Share compatibility results**. Then the reports also go
+to PostHog as `compat_report` events, and the maintainer syncs them in (below).
+
+## Community reports
+
+```sh
+python3 ui/frame_compat_db.py sync --dry-run   # what would be added
+python3 ui/frame_compat_db.py sync             # add them
+```
+
+`sync` reads `compat_report` events through PostHog's query API and adds
+them with `via` set to `community`, `community-probe` or `community-install`.
+It skips invalid reports and anything over 30 per reporter per day. Each run
+re-reads the last 30 days, because an offline copy sends its reports late,
+with the time they were made. `posthog-sync.json`, next to the outbox,
+remembers which reports it has handled and each reporter's daily count, so
+nothing is added twice and the cap holds across runs.
+
+It needs:
+
+- the PostHog project id: `"project"` in `ui/telemetry.json`
+- a personal API key with `query:read`: `POSTHOG_PERSONAL_API_KEY`, or in the
+  Keychain (service `frame-control-posthog`, account `personal-api-key`)
 
 - Live: `https://frame-compat.lakebed.app` (deploy `dep_dDmcsosVSiFirpW6`,
   claimed, so it doesn't expire). The browser page only says it's private.