Add Claude Code GitHub Workflow (#17615)

## 🤖 Installing Claude Code GitHub App

This PR adds a GitHub Actions workflow that enables Claude Code
integration in our repository.

### What is Claude Code?

[Claude Code](https://claude.com/claude-code) is an AI coding agent that
can help with:
- Bug fixes and improvements  
- Documentation updates
- Implementing new features
- Code reviews and suggestions
- Writing tests
- And more!

### How it works

Once this PR is merged, we'll be able to interact with Claude by
mentioning @claude in a pull request or issue comment.
Once the workflow is triggered, Claude will analyze the comment and
surrounding context, and execute on the request in a GitHub action.

### Important Notes

- **This workflow won't take effect until this PR is merged**
- **@claude mentions won't work until after the merge is complete**
- The workflow runs automatically whenever Claude is mentioned in PR or
issue comments
- Claude gets access to the entire PR or issue context including files,
diffs, and previous comments

### Security

- Our Anthropic API key is securely stored as a GitHub Actions secret
- Only users with write access to the repository can trigger the
workflow
- All Claude runs are stored in the GitHub Actions run history
- Claude's default tools are limited to reading/writing files and
interacting with our repo by creating comments, branches, and commits.
- We can add more allowed tools by adding them to the workflow file
like:

```
allowed_tools: Bash(npm install),Bash(npm run build),Bash(npm run lint),Bash(npm run test)
```

There's more information in the [Claude Code action
repo](https://github.com/anthropics/claude-code-action).

After merging this PR, let's try mentioning @claude in a comment on any
PR to get started!

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

.github/workflows/claude.yml

@@ -0,0 +1,75 @@
+name: Claude Code
+
+on:
+  issue_comment:
+    types: [created]
+  pull_request_review_comment:
+    types: [created]
+  pull_request_review:
+    types: [submitted]
+  issues:
+    types: [opened, assigned]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.issue.number || github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  claude:
+    if: |
+      (github.event_name == 'issue_comment' && contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request_review_comment' && contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request_review' && contains(github.event.review.body, '@claude')) ||
+      (github.event_name == 'issues' && (contains(github.event.issue.body, '@claude') || contains(github.event.issue.title, '@claude')))
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    permissions:
+      contents: write
+      pull-requests: write
+      issues: write
+      id-token: write
+      actions: read
+    services:
+      postgres:
+        image: postgres:16
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: postgres
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+      redis:
+        image: redis
+        ports:
+          - 6379:6379
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Install dependencies
+        uses: ./.github/actions/yarn-install
+      - name: Build shared dependencies
+        run: |
+          npx nx build twenty-shared
+          npx nx build twenty-emails
+      - name: Setup env files
+        run: |
+          npx nx reset:env twenty-front
+          npx nx reset:env twenty-server
+      - name: Create databases
+        run: |
+          PGPASSWORD=postgres psql -h localhost -p 5432 -U postgres -d postgres -c 'CREATE DATABASE "default";'
+          PGPASSWORD=postgres psql -h localhost -p 5432 -U postgres -d postgres -c 'CREATE DATABASE "test";'
+      - name: Run Claude Code
+        uses: anthropics/claude-code-action@v1
+        with:
+          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+          additional_permissions: |
+            actions: read
+          claude_args: "--max-turns 50"