feat: complete Tasks 21-28 — backend integration, security hardening, UI tests & CI

- Add Apple Sign-In backend (JWKS verification, account linking, session management)
- Implement push notification deep linking with NotificationDeepLinkRouter
- Add jailbreak detection, runtime integrity monitoring, secure enclave service
- Implement OAuth social login, token refresh, and secure logout flows
- Add image caching (memory/disk), optimizer, upload queue, async semaphore
- Implement notification analytics, type preferences, and category setup
- Expand UI test suite with UITestBase, accessibility, auth flow, performance tests
- Add CI pipeline for iOS UI tests (3 device sizes) and performance benchmarks
- Restructure Xcode project to manual groups with KordantWidgets target
- Add SwiftLint, Swift Collections/Algorithms/GoogleSignIn dependencies
- Update project.yml for XcodeGen with new targets and configurations

iOS/project.yml

@@ -26,6 +26,9 @@ packages:
   Algorithms:
     url: https://github.com/apple/swift-algorithms
     from: "1.0.0"
+  GoogleSignIn:
+    url: https://github.com/google/GoogleSignIn-iOS
+    from: "7.0.0"
 
 targets:
   Kordant:
@@ -34,19 +37,27 @@ targets:
     deploymentTarget: "17.0"
     sources:
       - path: Kordant
+        includes:
+          - "**/*.swift"
+          - "**/*.strings"
+          - "PrivacyInfo.xcprivacy"
         excludes:
           - "**/*.xcodeproj"
+      - path: Sources/Shared
     settings:
       base:
         PRODUCT_BUNDLE_IDENTIFIER: com.frenocorp.kordant
         PRODUCT_NAME: Kordant
         ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS: YES
-        INFOPLIST_FILE: Kordant/Info.plist
+        INFOPLIST_FILE: Info.plist
     dependencies:
+      - target: KordantWidgets
       - package: Collections
         product: Collections
       - package: Algorithms
         product: Algorithms
+      - package: GoogleSignIn
+        product: GoogleSignIn
     preBuildScripts:
       - name: SwiftLint
         script: |
@@ -71,6 +82,25 @@ targets:
     dependencies:
       - target: Kordant
 
+  KordantWidgets:
+    type: app-extension
+    platform: iOS
+    deploymentTarget: "17.0"
+    sources:
+      - path: KordantWidgets
+        includes:
+          - "**/*.swift"
+          - "PrivacyInfo.xcprivacy"
+      - path: Sources/Shared
+    settings:
+      base:
+        PRODUCT_BUNDLE_IDENTIFIER: com.frenocorp.kordant.widgets
+        PRODUCT_NAME: KordantWidgets
+        SKIP_INSTALL: YES
+        INFOPLIST_FILE: KordantWidgets/Info.plist
+        CODE_SIGN_ENTITLEMENTS: KordantWidgets/KordantWidgets.entitlements
+        SWIFT_VERSION: "5.9"
+
   KordantUITests:
     type: bundle.ui-testing
     platform: iOS
@@ -89,6 +119,7 @@ schemes:
     build:
       targets:
         Kordant: all
+        KordantWidgets: all
         KordantTests: [test]
         KordantUITests: [test]
     run: