storkit: create 449_bug_oauth_callback_url_ignores_port_cli_flag

.storkit/work/1_backlog/449_bug_oauth_callback_url_ignores_port_cli_flag.md

@@ -0,0 +1,27 @@
+---
+name: "OAuth callback URL ignores --port CLI flag"
+---
+
+# Bug 449: OAuth callback URL ignores --port CLI flag
+
+## Description
+
+OAuthState is initialized with `resolve_port()` (reads STORKIT_PORT env var, defaults to 3001) instead of the actual port the server is listening on. When the server is started with `--port 4000`, the OAuth callback URL is still generated as `http://localhost:3001/callback`, so the Anthropic redirect lands on the wrong server and the state parameter lookup fails with "Unknown or expired state parameter".
+
+## How to Reproduce
+
+Start storkit with `--port 4000` (without setting STORKIT_PORT env var). Click the OAuth login button in the web UI. Authenticate with Anthropic. The callback redirect goes to localhost:3001 instead of localhost:4000.
+
+## Actual Result
+
+Callback hits port 3001 (or wrong port). If a different storkit is running there, it returns "Invalid State". If nothing is running there, the page fails to load.
+
+## Expected Result
+
+Callback URL should use the actual server port (from --port CLI flag), so the redirect returns to the correct server instance.
+
+## Acceptance Criteria
+
+- [ ] build_routes receives the actual listening port and passes it to OAuthState::new
+- [ ] OAuth callback URL matches the port the server is actually listening on
+- [ ] Works with --port flag, STORKIT_PORT env var, and default port