style: apply ruff format and enforce it in CI

.git-blame-ignore-revs

@@ -0,0 +1,8 @@
+# Commits that only reformat code. Ignore them in blame:
+#
+#   git config blame.ignoreRevsFile .git-blame-ignore-revs
+#
+# GitHub's blame view applies this file automatically.
+
+# style: apply ruff format across the codebase
+6af294d26500d4ecd328477e4143ac523c31ac05

.github/CONTRIBUTING.md

@@ -65,8 +65,9 @@ bind-mounted:
 Run these locally before pushing:
 
 ```bash
-# Lint (matches the "Ruff" CI check)
+# Lint and formatting (both match the "Ruff" CI check)
 ruff check custom_components/taskmate tests scripts
+ruff format --check custom_components/taskmate tests scripts   # drop --check to fix
 
 # Cards and panel (matches the "ESLint" CI check)
 npm ci && npm run lint

.github/workflows/lint.yml

@@ -39,6 +39,9 @@ jobs:
       - name: Run ruff
         run: ruff check custom_components/taskmate tests scripts
 
+      - name: Check formatting
+        run: ruff format --check custom_components/taskmate tests scripts
+
   eslint:
     name: ESLint (cards + panel)
     runs-on: ubuntu-latest

.pre-commit-config.yaml

@@ -40,6 +40,7 @@ repos:
     hooks:
       - id: ruff
         args: [--fix]
+      - id: ruff-format
 
   - repo: local
     hooks: