iOS: Share Extension (share to Noo) via an App Group inbox

ShareExtension target copies shared files into group.dev.ayushya.noo and
leaves a manifest; the app consumes it on launch/activation through the
existing share_intent channel into the destination picker. Extension is
embedded before Flutter's script phases; versions follow FLUTTER_BUILD_*.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ios/RunnerTests/RunnerTests.swift

@@ -49,4 +49,52 @@ class RunnerTests: XCTestCase {
     FileManager.default.createFile(atPath: dir.appendingPathComponent("README").path, contents: nil)
     XCTAssertEqual(LocalFiles.uniqueURL(in: dir, name: "README").lastPathComponent, "README (1)")
   }
+
+  // MARK: - SharedInbox (Share Extension hand-off)
+
+  private func makeRoot() throws -> URL {
+    let root = FileManager.default.temporaryDirectory
+      .appendingPathComponent("noo-inbox-\(UUID().uuidString)", isDirectory: true)
+    try FileManager.default.createDirectory(at: root, withIntermediateDirectories: true)
+    addTeardownBlock { try? FileManager.default.removeItem(at: root) }
+    return root
+  }
+
+  private func makeSharedFile(in root: URL, name: String, contents: String = "hi") throws -> SharedItem {
+    let batch = try SharedInbox.makeBatchDirectory(in: root)
+    let file = batch.appendingPathComponent(name)
+    try contents.write(to: file, atomically: true, encoding: .utf8)
+    return SharedItem(path: file.path, name: name, mimeType: "text/plain", size: Int64(contents.utf8.count))
+  }
+
+  func testInboxConsumeReturnsAppendedItemsOnceThenNothing() throws {
+    let root = try makeRoot()
+    let a = try makeSharedFile(in: root, name: "a.txt")
+    let b = try makeSharedFile(in: root, name: "b.txt")
+    try SharedInbox.append([a], in: root)
+    try SharedInbox.append([b], in: root)
+
+    XCTAssertEqual(SharedInbox.consume(in: root), [a, b])
+    XCTAssertEqual(SharedInbox.consume(in: root), [], "each share is delivered once")
+  }
+
+  func testInboxConsumeDropsFilesThatNoLongerExist() throws {
+    let root = try makeRoot()
+    let kept = try makeSharedFile(in: root, name: "kept.txt")
+    let gone = try makeSharedFile(in: root, name: "gone.txt")
+    try SharedInbox.append([kept, gone], in: root)
+    try FileManager.default.removeItem(atPath: gone.path)
+
+    XCTAssertEqual(SharedInbox.consume(in: root), [kept])
+  }
+
+  func testInboxConsumeWithNothingPendingIsEmpty() throws {
+    XCTAssertEqual(SharedInbox.consume(in: try makeRoot()), [])
+  }
+
+  func testInboxAppendOfNothingCreatesNoManifest() throws {
+    let root = try makeRoot()
+    try SharedInbox.append([], in: root)
+    XCTAssertEqual(SharedInbox.consume(in: root), [])
+  }
 }