Capacitor 8 upgrade — Step A (keep CocoaPods)

Bump to Capacitor 8 while staying on CocoaPods (decouples the major-version bump
from the SPM switch, per the verified plan). Changes:
- mobile/package.json: all @capacitor/* + @capacitor-community/safe-area + cli → ^8.0.0
  (safe-area 8.0.1 verified Cap 8 compatible; @capacitor/assets stays 3.x, version-agnostic).
- 4 local plugins: @capacitor/core peer/dev dep → ^8.0.0; podspec ios deployment_target 14→15.
- codemagic.yaml: node 20→22 (Cap 8 requires Node 22+); `cap add ios --packagemanager Cocoapods`
  (Cap 8 defaults to SPM — force CocoaPods); fail loudly if no Podfile is generated.
- add-share-extension.rb: fallback deployment target 14→15.
Requirements per the Cap 7→8 guide: Node 22+, Xcode 26+, iOS 15 min. capacitor.config has no
adjustMarginsForEdgeToEdge to remove. LiveKit git-pins + native calling unchanged.

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

mobile/package.json

@@ -14,21 +14,21 @@
     "media-library": "file:plugins/media-library",
     "native-call": "file:plugins/native-call",
     "share-inbox": "file:plugins/share-inbox",
-    "@capacitor-community/safe-area": "^7.0.0",
-    "@capacitor/android": "^7.0.0",
-    "@capacitor/app": "^7.0.0",
-    "@capacitor/camera": "^7.0.0",
-    "@capacitor/core": "^7.0.0",
-    "@capacitor/filesystem": "^7.0.0",
-    "@capacitor/ios": "^7.0.0",
-    "@capacitor/keyboard": "^7.0.0",
-    "@capacitor/share": "^7.0.0",
-    "@capacitor/push-notifications": "^7.0.0",
-    "@capacitor/splash-screen": "^7.0.0",
-    "@capacitor/status-bar": "^7.0.0"
+    "@capacitor-community/safe-area": "^8.0.0",
+    "@capacitor/android": "^8.0.0",
+    "@capacitor/app": "^8.0.0",
+    "@capacitor/camera": "^8.0.0",
+    "@capacitor/core": "^8.0.0",
+    "@capacitor/filesystem": "^8.0.0",
+    "@capacitor/ios": "^8.0.0",
+    "@capacitor/keyboard": "^8.0.0",
+    "@capacitor/share": "^8.0.0",
+    "@capacitor/push-notifications": "^8.0.0",
+    "@capacitor/splash-screen": "^8.0.0",
+    "@capacitor/status-bar": "^8.0.0"
   },
   "devDependencies": {
     "@capacitor/assets": "^3.0.5",
-    "@capacitor/cli": "^7.0.0"
+    "@capacitor/cli": "^8.0.0"
   }
 }