chore: bootstrap Godot quality tools

docs/local_quality_gate.md

@@ -5,12 +5,20 @@ parser errors, and LLM-generated garbage before committing.
 
 ## Requirements
 
-- **Python 3** with `gdtoolkit` (gdscript-toolkit):
+- **Python 3** with the pinned `gdtoolkit` (gdscript-toolkit). The recommended
+  setup uses `uv` and a project-local environment:
+
   ```bash
-  pip install gdtoolkit
+  uv venv .venv
+  uv pip install --python .venv/bin/python -r requirements-dev.txt
   ```
+
+  On Windows, use `.venv/Scripts/python.exe` for the `--python` value.
 - **Godot 4** binary on `PATH`, or set the `GODOT_BIN` environment variable
 
+The quality and format scripts discover `.venv` automatically; activating it
+is optional.
+
 ## Usage
 
 ### Full project check
@@ -102,7 +110,7 @@ to the terminal.
 To add this to CI, install the dependencies and run:
 
 ```bash
-pip install gdtoolkit
+python -m pip install -r requirements-dev.txt
 ./tools/quality.sh
 ```