Add CI/CD pipelines for Lendair (iOS + web) [FRE-4690]

- iOS: swift lint, build verification, and test on PR
- Web: typecheck, vitest tests, build, and Vercel deployment (ready for web project)
- Package.swift: defines Lendair as buildable Swift package
- Test target: LendairTests with XCTest boilerplate

Co-Authored-By: Paperclip <noreply@paperclip.ing>

.github/workflows/ios-ci.yml

@@ -0,0 +1,72 @@
+name: iOS CI
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "Lendair/**"
+      - ".github/workflows/ios-ci.yml"
+  pull_request:
+    branches: [main]
+    paths:
+      - "Lendair/**"
+      - ".github/workflows/ios-ci.yml"
+
+concurrency:
+  group: ios-ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    name: Swift Lint
+    runs-on: macos-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Select Xcode
+        run: sudo xcode-select -s /Applications/Xcode_15.4.app
+
+      - name: Swift Format Check
+        run: |
+          swift format --format --recursive Lendair/Models Lendair/Services Lendair/ViewModels Lendair/Views 2>/dev/null || true
+          if ! swift format --lint --recursive Lendair/Models Lendair/Services Lendair/ViewModels Lendair/Views 2>/dev/null; then
+            echo "::warning::Swift format issues detected (non-blocking)"
+          fi
+
+  build:
+    name: Build
+    runs-on: macos-latest
+    needs: lint
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Select Xcode
+        run: sudo xcode-select -s /Applications/Xcode_15.4.app
+
+      - name: Swift version
+        run: swift --version
+
+      - name: Resolve dependencies
+        run: swift package resolve
+        working-directory: Lendair
+
+      - name: Build
+        run: swift build -c release
+        working-directory: Lendair
+
+  test:
+    name: Test
+    runs-on: macos-latest
+    needs: build
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Select Xcode
+        run: sudo xcode-select -s /Applications/Xcode_15.4.app
+
+      - name: Run tests
+        run: swift test
+        working-directory: Lendair