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>

assets/ui-icons/input-apple-tv.svg

@@ -0,0 +1 @@
+<svg viewBox="0 0 24 24" aria-hidden="true" data-connection-icon="apple-tv" fill="currentColor" xmlns="http://www.w3.org/2000/svg" width="128" height="128" color="#fff"><path d="M20.57 17.735h-1.815l-3.34-9.203h1.633l2.02 5.987c.075.231.273.9.586 2.012l.297-.997.33-1.006 2.094-6.004H24zm-5.344-.066a5.76 5.76 0 0 1-1.55.207c-1.23 0-1.84-.693-1.84-2.087V9.646h-1.063V8.532h1.121V7.081l1.476-.602v2.062h1.707v1.113H13.38v5.805c0 .446.074.75.214.932.14.182.396.264.75.264.207 0 .495-.041.883-.115zm-7.29-5.343c.017 1.764 1.55 2.358 1.567 2.366-.017.042-.248.842-.808 1.658-.487.71-.99 1.418-1.79 1.435-.783.016-1.03-.462-1.93-.462-.89 0-1.17.445-1.913.478-.758.025-1.344-.775-1.838-1.484-.998-1.451-1.765-4.098-.734-5.88.51-.89 1.426-1.451 2.416-1.46.75-.016 1.468.512 1.93.512.461 0 1.327-.627 2.234-.536.38.016 1.452.157 2.136 1.154-.058.033-1.278.743-1.27 2.219M6.468 7.988c.404-.495.685-1.18.61-1.864-.585.025-1.294.388-1.723.883-.38.437-.71 1.138-.619 1.806.652.05 1.328-.338 1.732-.825Z"></path></svg>