cursor(rules[dev-loop]) add pytest-watcher commands for continuous testing

Author: tony

.cursor/rules/dev-loop.mdc

@@ -21,6 +21,19 @@ Verify that your changes pass the tests:
 uv run py.test
 ```
 
+For continuous testing during development, use pytest-watcher:
+
+```
+# Watch all tests
+uv run ptw .
+
+# Watch and run tests immediately, including doctests
+uv run ptw . --now --doctest-modules
+
+# Watch specific files or directories
+uv run ptw . --now --doctest-modules src/libtmux/_internal/
+```
+
 ## 3. Commit Initial Changes
 
 Make an atomic commit for your changes using conventional commits.
@@ -126,3 +139,9 @@ For doctests in `src/**/*.py` files:
 4. **Keep doctests simple and focused** on demonstrating usage rather than comprehensive testing.
 
 5. **Add blank lines between test sections** for improved readability.
+
+6. **Test your doctests continuously** using pytest-watcher during development:
+   ```
+   # Watch specific modules for doctest changes
+   uv run ptw . --now --doctest-modules src/path/to/module.py
+   ```