feat(ios): hoist DebugBridgeTouch into canonical templates

Bridges.swift.template imports DebugBridgeTouch but no .m/.h template
shipped — consuming apps installing the canonical drop-in would hit a
linker error. Closes that gap with the fixture's verified working code.

Changes:

- New ios-qa/templates/DebugBridgeTouch.{h,m}.template files (carbon
  copies of the fixture sources, including the iOS-18+ SwiftUI hit-test
  fix verified on iPhone 17 Pro Max).
- Package.swift.template splits into 3 product targets: DebugBridgeCore
  (Swift, cross-platform), DebugBridgeUI (Swift, iOS-only), DebugBridgeTouch
  (Obj-C, iOS-only). Consuming app adds one dependency on DebugBridgeUI;
  Core + Touch come in transitively.
- DebugBridgeTouch sources wrap their body in #if TARGET_OS_IOS so the
  cross-platform `swift build` on macOS host doesn't choke on UIKit. On
  iOS the real implementation is active; on macOS sendTapAtPoint: is a
  no-op returning NO.
- New parity tests pin template ↔ fixture content so future fixture
  fixes propagate or fail loudly.
- Restrict swift-build host tests to DebugBridgeCore (the only target
  buildable on macOS) and bring up the previously broken XCTest run via
  --filter.

Verified post-change: real iPhone 17 Pro Max, iOS 26.5, three /tap
requests against the rebuilt app — counter went 0 → 3, SwiftUI Button
onTap fires every time. Templates now sufficient to ship to any
consuming iOS app.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ios-qa/templates/Package.swift.template

@@ -1,8 +1,19 @@
 // AUTO-GENERATED from gstack/ios-qa/templates/Package.swift.template
 //
-// Drop-in SPM package definition for the DebugBridge target. The structural
-// Release-build guard is the `.when(configuration: .debug)` conditional on
-// every target dependency. SwiftPM refuses to link DebugBridge in Release.
+// Drop-in SPM package definition for the DebugBridge stack. Three targets:
+//
+//   - DebugBridgeCore   Swift, cross-platform (Foundation + Network).
+//                       Hosts the StateServer + bridge protocols.
+//   - DebugBridgeTouch  Objective-C, iOS-only. KIF-derived in-process touch
+//                       synthesis (UITouch + IOHIDEvent + iOS 18
+//                       _UIHitTestContext for SwiftUI Buttons).
+//   - DebugBridgeUI     Swift, iOS-only. ScreenshotBridge, ElementsBridge,
+//                       MutationBridge implementations. Depends on the other
+//                       two.
+//
+// The structural Release-build guard is the `.when(configuration: .debug)`
+// conditional on every consuming target's dependency. SwiftPM refuses to link
+// DebugBridge* in Release config.
 //
 // CI invariant: `swift build -c release` + `nm -j build/Release/<binary>
 // | grep -q DebugBridge && exit 1`.
@@ -14,25 +25,43 @@ let package = Package(
     name: "DebugBridge",
     platforms: [.iOS(.v16), .macOS(.v13)],
     products: [
-        .library(name: "DebugBridge", targets: ["DebugBridge"]),
+        .library(name: "DebugBridgeCore", targets: ["DebugBridgeCore"]),
+        .library(name: "DebugBridgeUI", targets: ["DebugBridgeUI"]),
+        .library(name: "DebugBridgeTouch", targets: ["DebugBridgeTouch"]),
     ],
     targets: [
         .target(
-            name: "DebugBridge",
+            name: "DebugBridgeCore",
             dependencies: [],
-            path: "Sources/DebugBridge",
+            path: "Sources/DebugBridgeCore",
+            swiftSettings: [
+                .define("DEBUG", .when(configuration: .debug)),
+            ]
+        ),
+        .target(
+            name: "DebugBridgeTouch",
+            dependencies: [],
+            path: "Sources/DebugBridgeTouch",
+            publicHeadersPath: "include",
+            linkerSettings: [
+                // IOKit is loaded dynamically via dlopen at runtime (it's a
+                // private framework on iOS and can't be linked statically).
+                // UIKit links normally.
+                .linkedFramework("UIKit", .when(platforms: [.iOS])),
+            ]
+        ),
+        .target(
+            name: "DebugBridgeUI",
+            dependencies: ["DebugBridgeCore", "DebugBridgeTouch"],
+            path: "Sources/DebugBridgeUI",
             swiftSettings: [
-                // Belt and suspenders. The host app's `.when(configuration: .debug)`
-                // condition on the dependency means we never link in Release. This
-                // setting additionally fails the build with a clear error if a
-                // user somehow forces the build.
                 .define("DEBUG", .when(configuration: .debug)),
             ]
         ),
         .testTarget(
-            name: "DebugBridgeTests",
-            dependencies: ["DebugBridge"],
-            path: "Tests/DebugBridgeTests"
+            name: "DebugBridgeCoreTests",
+            dependencies: ["DebugBridgeCore"],
+            path: "Tests/DebugBridgeCoreTests"
         ),
     ]
 )