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>

Lendair/LendairTests/LendairTests.swift

@@ -0,0 +1,7 @@
+import XCTest
+
+class LendairTests: XCTestCase {
+    func testPackageLoads() throws {
+        XCTAssertTrue(true)
+    }
+}