Frame Control: Mac app, web UI, Android and Steam tooling

Package the Frame Control web UI as an installable Electron Mac app and
bring in the tooling built alongside it.

- app/: Electron wrapper that starts ui/server.py on a free loopback port,
  hardened window (sandbox, no navigation, runAsNode fuse off), login-shell
  PATH so Homebrew tools work from Finder, first-run offer to run
  connect.sh, ad-hoc signed DMG/zip via electron-builder.
- ui/: headset view (OpenVR screenshots), device status, library, Steam
  "Get games" (owned games, install, store search), Android apps as
  persistent Lepton instances with a rated F-Droid catalogue and a private
  compatibility database, Android display controls over ADB, file and
  clipboard transfer, Flatpaks, remote and power actions.
- apk-catalog/, compat-db/, frame/: catalogue build pipeline, Lakebed
  capsule for compatibility reports, Frame-side launchers.
- tests/ and CI: server guard and validation tests plus Steam helper tests,
  run on Python 3.9 with script and app syntax checks.
- Docs: README leads with the Mac app; new Android, panels, Steam games and
  field-notes docs; security notes on LAN-exposed ADB ports.

Screenshot values for the headset's IP and Wi-Fi name are placeholders.

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

.github/workflows/checks.yml

@@ -0,0 +1,34 @@
+name: checks
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  checks:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.9"   # the oldest python3 the Mac app may pick up (Xcode CLT)
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "24"
+      - name: Install zsh
+        run: sudo apt-get update -qq && sudo apt-get install -y -qq zsh
+      - name: Script syntax
+        run: |
+          for f in scripts/*.sh frame/*/*.sh; do
+            case "$(head -n 1 "$f")" in
+              *zsh*) zsh -n "$f" ;;
+              *) bash -n "$f" ;;
+            esac
+          done
+      - name: Python compiles
+        run: python -m py_compile ui/*.py apk-catalog/*.py frame/android/*.py
+      - name: Server tests
+        run: python -m unittest discover -s tests -v
+      - name: App syntax
+        run: node --check app/main.js && node --check app/build/make-icon.js