speaker: make AudioRoute a real Capacitor plugin PACKAGE so it registers (device log: has:0)

Device telemetry proved the app-embedded AudioRoute class never registered (not in
Capacitor.Plugins) — appending a CAPBridgedPlugin to AppDelegate.swift gets stripped/undiscovered
in release builds. The plugins that DO register (Share, Camera, Filesystem) are all npm packages
wired by cap sync. So AudioRoute is now a local plugin package (mobile/plugins/audio-route,
file: dep in mobile/package.json) with a podspec + CAPBridgedPlugin Swift — cap sync adds its pod
and Capacitor registers it like the others. load() sets the launch speaker default; setSpeaker({on})
overrides the output port. inject-audio.js no longer injects the plugin class (would duplicate);
it keeps only the AppDelegate launch default as a fallback.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

mobile/plugins/audio-route/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "audio-route",
+  "version": "1.0.0",
+  "description": "iOS earpiece/speaker audio route toggle for Biz Connect",
+  "main": "dist/plugin.cjs.js",
+  "module": "dist/esm/index.js",
+  "types": "dist/esm/index.d.ts",
+  "author": "BizGaze",
+  "license": "MIT",
+  "files": [
+    "dist/",
+    "ios/",
+    "AudioRoutePlugin.podspec"
+  ],
+  "capacitor": {
+    "ios": {
+      "src": "ios"
+    }
+  },
+  "devDependencies": {
+    "@capacitor/core": "^7.0.0"
+  },
+  "peerDependencies": {
+    "@capacitor/core": "^7.0.0"
+  }
+}