Add GitHub Actions workflow for linting with Ruff

.github/workflows/lint-pr.yml

@@ -0,0 +1,61 @@
+name: Lint with Ruff
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    permissions:
+      pull-requests: write
+      issues: write
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Install uv
+      uses: astral-sh/setup-uv@v4
+
+    - name: Set up Python
+      run: uv python install
+
+    - name: Install the project
+      run: uv sync --all-extras --dev
+
+    - name: Run Ruff
+      id: run_ruff
+      run: |
+        uv run ruff check . > ruff_output.txt || true
+
+    - name: Post PR comment
+      uses: actions/github-script@v6
+      with:
+        script: |
+          const fs = require('fs');
+          const { data: comments } = await github.rest.issues.listComments({
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            issue_number: context.payload.pull_request.number,
+          });
+
+          const botComment = comments.find(comment => comment.user.login === 'github-actions[bot]');
+          const body = `## Ruff\n\`\`\`\n${fs.readFileSync('ruff_output.txt', 'utf8')}\n\`\`\``;
+
+          if (botComment) {
+            await github.rest.issues.updateComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              comment_id: botComment.id,
+              body,
+            });
+          } else {
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.payload.pull_request.number,
+              body,
+            });
+          }