chore: remove iOS CI/CD workflow per project decision

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.github/workflows/ios-ci.yml

@@ -1,48 +0,0 @@
-name: iOS CI/CD
-
-on:
-  push:
-    branches: [main, develop]
-  pull_request:
-    branches: [main]
-
-jobs:
-  build-and-test:
-    name: Build & Test
-    runs-on: macos-15
-    timeout-minutes: 30
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Select Xcode
-        run: sudo xcode-select -s /Applications/Xcode.app
-
-      - name: Build Rust xcframework (arm64 sim)
-        working-directory: ../zhixi-document-runtime
-        run: |
-          rustup target add aarch64-apple-ios-sim
-          cargo build --release -p zx_document_ffi --target aarch64-apple-ios-sim
-
-      - name: Build for iOS Simulator
-        run: |
-          xcodebuild build \
-            -project AIStudyApp/AIStudyApp.xcodeproj \
-            -scheme AIStudyApp \
-            -destination 'platform=iOS Simulator,name=iPhone 16' \
-            CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO
-
-      - name: Run Tests
-        run: |
-          xcodebuild test \
-            -project AIStudyApp/AIStudyApp.xcodeproj \
-            -scheme AIStudyApp \
-            -destination 'platform=iOS Simulator,name=iPhone 16' \
-            CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO \
-            2>&1 | tee xcode-test.log
-
-      - name: Upload test log
-        if: always()
-        uses: actions/upload-artifact@v4
-        with:
-          name: xcode-test-log
-          path: xcode-test.log