feat: add iOS support and harden receipt scanning

app/ios/ScanReceipts/Networking/ProjectsAPI.swift

@@ -0,0 +1,32 @@
+import Foundation
+
+/// `/api/projects` — Pro-only folders. `list()` itself is not gated (a
+/// downgraded Pro user can still see how their receipts were filed), but
+/// create/rename/delete return `402 pro_required` for a free-plan account —
+/// surface that as a paywall prompt, not a generic error.
+enum ProjectsAPI {
+    static func list() async throws -> [Project] {
+        let response: ProjectListResponse = try await APIClient.shared.send(
+            APIRequest(path: "/api/projects", method: .get)
+        )
+        return response.projects
+    }
+
+    @discardableResult
+    static func create(name: String, color: String?) async throws -> Project {
+        struct Response: Decodable { let success: Bool; let project: Project }
+        let request = try APIRequest.json(
+            path: "/api/projects",
+            method: .post,
+            body: CreateProjectRequest(name: name, color: color)
+        )
+        let response: Response = try await APIClient.shared.send(request)
+        return response.project
+    }
+
+    static func delete(id: String) async throws {
+        try await APIClient.shared.sendDiscardingResponse(
+            APIRequest(path: "/api/projects/\(id)", method: .delete)
+        )
+    }
+}