Merge Luma launcher fork into monorepo

Move trampoline files (boot-hook, watcher, overlay) into trampoline/
subdirectory. Add upstream Luma v2.3.1 source at repo root with our
additions:

- Page::Ha (4th nav tab) with placeholder empty state
- HA tab config schema and default entity mapping (ha-home/)
- Nav keys renamed: "home" → "start", new "ha" tab between Apps and Settings
- All state.rs/view.rs/main.rs/tests.rs updated for 4-tab navigation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

appinfo.json

@@ -0,0 +1,18 @@
+{
+  "id": "com.ecklf.luma",
+  "version": "2.3.1",
+  "vendor": "Luma",
+  "type": "native",
+  "main": "luma",
+  "title": "Luma",
+  "icon": "app-icon.png",
+  "largeIcon": "app-icon-large.png",
+  "appDescription": "A remote-first native webOS launcher.",
+  "resolution": "1920x1080",
+  "appCategory": ["home"],
+  "requiredACG": ["application.launcher", "application.query", "lunabus.query"],
+  "handlesRelaunch": false,
+  "iconColor": "#25272d",
+  "splashBackground": "splash.png",
+  "bgColor": "#17191c"
+}