chore: remove local testing scripts, docker demo env, and screenshots from repo

- gitignore deploy/ and gui-test-screenshots/ (local dev artifacts, not for repo)
- README: remove deploy section and build path reference
- Files kept on disk for local use, just untracked

.gitignore

@@ -23,11 +23,10 @@ data/
 
 # docker demo staging (frp binaries)
 frp-bin/
-deploy/frp-bin/
 
-# demo runtime data + compiled artifacts (regenerable)
-deploy/data/
-deploy/artifacts/
+# local testing scripts, docker demo env, and screenshots (not for repo)
+deploy/
+gui-test-screenshots/
 
 # vendored deps (regenerable; keep out of git)
 vendor/