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>

.oxlintrc.json

@@ -0,0 +1,11 @@
+{
+  "$schema": "./node_modules/oxlint/configuration_schema.json",
+  "plugins": ["oxc"],
+  "categories": {
+    "correctness": "error"
+  },
+  "rules": {
+    "eslint/no-unused-vars": ["error", { "argsIgnorePattern": "^_" }]
+  },
+  "ignorePatterns": ["node_modules/**", "dist/**", ".build/**", "target/**"]
+}