feat: add ty type checker alongside mypy (#77)

Add Astral's ty type checker (written in Rust, 10-100x faster than mypy)
as a second type checking layer. Both run in pre-commit and CI.

Fixed type issues caught by ty:
- config.py: explicit Host constructor to avoid dict unpacking issues
- executor.py: wrap subprocess.run in closure for asyncio.to_thread
- api.py: use getattr for Jinja TemplateModule macro access
- test files: fix playwright driver_path tuple handling, pytest rootpath typing

.pre-commit-config.yaml

@@ -25,13 +25,18 @@ repos:
         args: [--fix]
       - id: ruff-format
 
-  - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.14.0
+  - repo: local
     hooks:
       - id: mypy
-        exclude: ^docs/demos/
-        additional_dependencies:
-          - pydantic>=2.0.0
-          - typer>=0.9.0
-          - asyncssh>=2.14.0
-          - types-PyYAML
+        name: mypy (type checker)
+        entry: uv run mypy src tests
+        language: system
+        types: [python]
+        pass_filenames: false
+
+      - id: ty
+        name: ty (type checker)
+        entry: uv run ty check
+        language: system
+        types: [python]
+        pass_filenames: false