docs: add Cursor Cloud specific setup instructions to AGENTS.md (#86)

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Piotr Wodecki <PiotrWodecki@users.noreply.github.com>

Author: PiotrWodecki

AGENTS.md

@@ -11,3 +11,10 @@ Whenever a new feature is added, follow the red-green TDD cycle:
 3. **Refactor** — clean up the implementation and tests while keeping the suite green.
 
 Do not write production code for a new feature before a failing test exists for it.
+
+## Cursor Cloud specific instructions
+
+`uv` is pre-installed; the startup script runs `uv sync`. Non-obvious notes:
+
+- Validated: `uv sync`, `uv run ruff check .`, and a smoke import (`uv run python -c "import fishjam"`).
+- The `tests/` suite is integration-oriented: `tests/conftest.py` imports `FISHJAM_ID` and `FISHJAM_MANAGEMENT_TOKEN` at collection time, so `uv run pytest` fails with `KeyError` unless those env vars are set and a live Fishjam server is reachable. The unit-style tests run with placeholders, e.g. `FISHJAM_ID=dummy FISHJAM_MANAGEMENT_TOKEN=dummy uv run pytest tests/test_config_validation.py tests/test_allowed_notifications.py`.