Add scan flow MVP and local Axiom skill workspace

This snapshot establishes the camera-to-result recognition flow and related tests while checking in the project skill/docs assets required for the configured local tooling.

StackDex/Services/FoundationModelEnhancer.swift

@@ -0,0 +1,14 @@
+import Foundation
+
+protocol CardFieldEnhancing {
+    func enhance(draft: CardRecognitionDraft, rawText: String) async -> CardRecognitionDraft
+}
+
+struct NoOpCardFieldEnhancer: CardFieldEnhancing {
+    func enhance(draft: CardRecognitionDraft, rawText: String) async -> CardRecognitionDraft {
+        // TODO: Replace this with a Foundation Models-backed enhancer once the runtime
+        // integration is ready and verified locally. Keeping the boundary injectable means
+        // the call site stays stable while the MVP compiles cleanly today.
+        draft
+    }
+}