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>

trampoline/boot-hook.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+# Luma Home trampoline — bind-mount a transparent web page over LG Home,
+# then launch Luma on top. A subscription watcher re-launches Luma every
+# time the Home button is pressed (backup for when WebOSServiceBridge in
+# the web page does not fire).
+#
+# Install:
+#   ln -sf /media/developer/luma-home/boot-hook.sh /var/lib/webosbrew/init.d/10-luma-home
+#
+# Requires: Homebrew Channel, Luma (com.ecklf.luma) installed via IPK.
+# Tested on: webOS 6.5.3-47 (LG 65NANO813PA)
+
+export PATH=/usr/bin:/usr/sbin:/bin:/sbin:$PATH
+L=/media/developer/luma-home
+H=/usr/palm/applications/com.webos.app.home
+
+kill $(cat /tmp/luma-watcher.pid 2>/dev/null) 2>/dev/null
+
+if ! grep -q " $H " /proc/mounts; then
+  mount --bind $L/overlay $H
+  systemctl restart sam
+  i=0
+  while [ $i -lt 30 ]; do
+    systemctl is-active sam >/dev/null 2>&1 && break
+    sleep 2; i=$((i+1))
+  done
+  sleep 5
+  luna-send -n 1 -w 10000 -f luna://com.webos.applicationManager/launch '{ "id": "com.ecklf.luma" }' </dev/null >/dev/null 2>&1
+fi
+
+nohup $L/watcher.sh </dev/null >/dev/null 2>&1 &