Add Claude Code GitHub Workflow (#158)

## 🤖 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.ai/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!

Author: chrisguidry

.github/workflows/claude-code-review.yml

@@ -0,0 +1,40 @@
+name: Claude Code Review
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+jobs:
+  claude-review:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: read
+      issues: read
+      id-token: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Run Claude Code Review
+        id: claude-review
+        uses: anthropics/claude-code-action@beta
+        with:
+          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+          model: "claude-opus-4-1-20250805"
+
+          # Direct prompt for automated review (no @claude mention needed)
+          direct_prompt: |
+            Please review this pull request and provide feedback on:
+            - Code quality and best practices
+            - Potential bugs or issues
+            - Performance considerations
+            - Security concerns
+            - Test coverage, which must be maintained at 100% for this project
+
+            Be constructive and helpful in your feedback.
+
+          use_sticky_comment: true

.github/workflows/claude.yml

@@ -0,0 +1,42 @@
+name: Claude Code
+
+on:
+  issue_comment:
+    types: [created]
+  pull_request_review_comment:
+    types: [created]
+  issues:
+    types: [opened, assigned]
+  pull_request_review:
+    types: [submitted]
+
+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
+    permissions:
+      contents: read
+      pull-requests: read
+      issues: read
+      id-token: write
+      actions: read # Required for Claude to read CI results on PRs
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Run Claude Code
+        id: claude
+        uses: anthropics/claude-code-action@beta
+        with:
+          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+
+          additional_permissions: |
+            actions: read
+
+          model: "claude-opus-4-1-20250805"