Add ty type checking to CI and pre-commit

- Add ty to the dev dependency group (pinned via uv.lock at 0.0.51).
- lint.yml: new parallel `ty` job running `uv run ty check custom_components/`
  so ty type-checks against the integration's installed dependencies (the
  fast `uvx ruff` job stays project-sync-free).
- .pre-commit-config.yaml: add ty as a local hook (`uv run ty check`) using
  the same project env; the official ty-pre-commit hook runs in an isolated
  env without the project's deps and would report false unresolved imports.

Author: bkanuka

.github/workflows/lint.yml

@@ -30,3 +30,21 @@ jobs:
 
       - name: Format
         run: uvx ruff format . --check
+
+  ty:
+    name: "ty"
+    runs-on: "ubuntu-latest"
+    steps:
+      - name: Checkout the repository
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+
+      - name: Set up uv
+        uses: astral-sh/setup-uv@fac544c07dec837d0ccb6301d7b5580bf5edae39 # v8.2.0
+        with:
+          enable-cache: true
+
+      # ty needs the integration's dependencies to resolve imports, so run it
+      # through `uv run` (which syncs the project's .venv first). The version is
+      # pinned via the dev dependency group in uv.lock.
+      - name: Type check
+        run: uv run ty check custom_components/

.pre-commit-config.yaml

@@ -7,3 +7,15 @@ repos:
       - id: ruff-check
         args: ["--fix", "--unsafe-fixes", "--show-fixes"]
       - id: ruff-format
+  - repo: local
+    hooks:
+      - id: ty
+        name: ty
+        # Run ty from the uv project so it type-checks against the
+        # integration's installed dependencies (resolved via .venv). Uses the
+        # ty version pinned in the dev dependency group / uv.lock.
+        entry: uv run ty check custom_components/
+        language: system
+        types: [python]
+        pass_filenames: false
+        require_serial: true

pyproject.toml

@@ -19,6 +19,7 @@ dev = [
     "pip>=21.3.1",
     "pre-commit>=4.5.0",
     "ruff>=0.15",
+    "ty>=0.0.51",
 ]
 
 # This is a Home Assistant / HACS integration, not a Python package: HACS ships