Validate dev runner port overrides and honor env state dir

- Prefer `T3CODE_STATE_DIR` from env when `--state-dir` is unset or blank
- Throw on invalid `T3CODE_PORT` overrides and always recompute `VITE_WS_URL`
- Add tests for env/state-dir precedence, blank overrides, and invalid ports
335d6ac076Julius Marminge committed on 2/27/2026, 2:33:21 AMparent67f95ee
2 files changedLine totals unavailable