Native calls: get LiveKit 2.15.3 via git-tag pin (stay on CocoaPods) + audio fix

The LiveKitClient CocoaPod on trunk caps at 2.0.18 (2.1+ is SPM-only), so the
2.15 CallKit audio API was unreachable. BUT the repo still ships a valid podspec
at tag 2.15.3, and its deps (LiveKitWebRTC 144.7559.11, LiveKitUniFFI 0.0.6,
SwiftProtobuf) ARE on trunk. So instead of a risky SPM migration:
- ios-patch.sh injects `pod 'LiveKitClient', :git => <repo>, :tag => '2.15.3'`
  into the generated Podfile (after cap sync, before pod install). The NativeCall
  podspec's '~> 2.0' is satisfied by 2.15.3. Idempotent; hard-fails if it can't
  find the App target so we never silently fall back to 2.0.18.
- Plugin re-adds the CallKit<->LiveKit audio-session coordination, now compilable:
  auto-config OFF + engine OFF at load; configure session + enable engine in
  didActivate; disable in didDeactivate; request mic permission on connect.

Core Room APIs (connect/disconnect/setMicrophone) verified compatible between
2.0.18 and 2.15.3 against the real source.

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

pkg.swift

@@ -0,0 +1,78 @@
+// swift-tools-version:6.1
+// (Xcode16.3+)
+
+import PackageDescription
+
+let package = Package(
+    name: "LiveKit",
+    platforms: [
+        .iOS(.v13),
+        .macOS(.v10_15),
+        .macCatalyst(.v14),
+        .tvOS(.v17),
+    ],
+    products: [
+        .library(
+            name: "LiveKit",
+            targets: ["LiveKit"],
+        ),
+    ],
+    dependencies: [
+        // LK-Prefixed Dynamic WebRTC XCFramework
+        .package(url: "https://github.com/livekit/webrtc-xcframework.git", exact: "144.7559.11"),
+        .package(url: "https://github.com/livekit/livekit-uniffi-xcframework.git", exact: "0.0.6"),
+        .package(url: "https://github.com/apple/swift-protobuf.git", from: "1.31.0"),
+        // Only used for DocC generation
+        .package(url: "https://github.com/apple/swift-docc-plugin.git", from: "1.3.0"),
+    ],
+    targets: [
+        .target(
+            name: "LKObjCHelpers",
+            publicHeadersPath: "include",
+        ),
+        .target(
+            name: "LiveKit",
+            dependencies: [
+                .product(name: "LiveKitWebRTC", package: "webrtc-xcframework"),
+                .product(name: "LiveKitUniFFI", package: "livekit-uniffi-xcframework"),
+                .product(name: "SwiftProtobuf", package: "swift-protobuf"),
+                "LKObjCHelpers",
+            ],
+            exclude: [
+                "Broadcast/NOTICE",
+            ],
+            resources: [
+                .process("PrivacyInfo.xcprivacy"),
+            ],
+        ),
+        .target(
+            name: "LiveKitTestSupport",
+            dependencies: [
+                "LiveKit",
+            ],
+            path: "Tests/LiveKitTestSupport",
+        ),
+        .testTarget(
+            name: "LiveKitCoreTests",
+            dependencies: [
+                "LiveKit",
+                "LiveKitTestSupport",
+            ],
+        ),
+        .testTarget(
+            name: "LiveKitAudioTests",
+            dependencies: [
+                "LiveKit",
+                "LiveKitTestSupport",
+            ],
+        ),
+        .testTarget(
+            name: "LiveKitObjCTests",
+            dependencies: [
+                "LiveKit",
+                "LiveKitTestSupport",
+            ],
+        ),
+    ],
+    swiftLanguageModes: [.v5, .v6],
+)