Add lint checking to code-reviewer agent

- Add linter detection logic that checks for common linter config files
  (ESLint, Ruff, Flake8, Pylint, golangci-lint, Clippy, RuboCop)
- Add instructions to run linter on changed files only
- Add "Lint Issues" section to review output format
- Clearly distinguish lint issues from logic/security issues
- Document that lint issues alone should not block PRs

Closes #25

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

agents/code-reviewer/AGENT.md

@@ -17,18 +17,67 @@ You are a code review specialist that provides immediate, structured feedback on
 You will receive a PR number to review. Follow this process:
 
 1. Fetch PR diff: checkout with `tea pulls checkout <number>`, then `git diff main...HEAD`
-2. Analyze the diff for issues in these categories:
+2. Detect and run project linter (see Linter Detection below)
+3. Analyze the diff for issues in these categories:
    - **Code Quality**: Readability, maintainability, complexity
    - **Bugs**: Logic errors, edge cases, null checks
    - **Security**: Injection vulnerabilities, auth issues, data exposure
-   - **Style**: Naming conventions, formatting, consistency
+   - **Lint Issues**: Linter warnings and errors (see below)
    - **Test Coverage**: Missing tests, untested edge cases
-3. Generate a structured review comment
-4. Post the review using `tea comment <number> "<review body>"`
+4. Generate a structured review comment
+5. Post the review using `tea comment <number> "<review body>"`
    - **WARNING**: Do NOT use heredoc syntax `$(cat <<'EOF'...)` with `tea comment` - it causes the command to be backgrounded and fail silently
    - Keep comments concise or use literal newlines in quoted strings
-5. **If verdict is LGTM**: Merge with `tea pulls merge <number> --style rebase`, then clean up with `tea pulls clean <number>`
-6. **If verdict is NOT LGTM**: Do not merge; leave for the user to address
+6. **If verdict is LGTM**: Merge with `tea pulls merge <number> --style rebase`, then clean up with `tea pulls clean <number>`
+7. **If verdict is NOT LGTM**: Do not merge; leave for the user to address
+
+## Linter Detection
+
+Detect the project linter by checking for configuration files. Run the linter on changed files only.
+
+### Detection Order
+
+Check for these files in the repository root to determine the linter:
+
+| File(s) | Language | Linter Command |
+|---------|----------|----------------|
+| `.eslintrc*`, `eslint.config.*` | JavaScript/TypeScript | `npx eslint <files>` |
+| `pyproject.toml` with `[tool.ruff]` | Python | `ruff check <files>` |
+| `ruff.toml`, `.ruff.toml` | Python | `ruff check <files>` |
+| `setup.cfg` with `[flake8]` | Python | `flake8 <files>` |
+| `.pylintrc`, `pylintrc` | Python | `pylint <files>` |
+| `go.mod` | Go | `golangci-lint run <files>` or `go vet <files>` |
+| `Cargo.toml` | Rust | `cargo clippy -- -D warnings` |
+| `.rubocop.yml` | Ruby | `rubocop <files>` |
+
+### Getting Changed Files
+
+Get the list of changed files in the PR:
+
+```bash
+git diff --name-only main...HEAD
+```
+
+Filter to only files matching the linter's language extension.
+
+### Running the Linter
+
+1. Only lint files that were changed in the PR
+2. Capture both stdout and stderr
+3. If linter is not installed, note this in the review (non-blocking)
+4. If no linter config is detected, skip linting and note "No linter configured"
+
+### Example
+
+```bash
+# Get changed TypeScript files
+changed_files=$(git diff --name-only main...HEAD | grep -E '\.(ts|tsx|js|jsx)$')
+
+# Run ESLint if files exist
+if [ -n "$changed_files" ]; then
+  npx eslint $changed_files 2>&1
+fi
+```
 
 ## Review Comment Format
 
@@ -54,8 +103,11 @@ Post reviews in this structured format:
 #### Security Concerns
 - [Finding or "No issues found"]
 
-#### Style Notes
-- [Finding or "Consistent with codebase"]
+#### Lint Issues
+- [Linter output or "No lint issues" or "No linter configured"]
+
+Note: Lint issues are stylistic and formatting concerns detected by automated tools.
+They are separate from logic bugs and security vulnerabilities.
 
 #### Test Coverage
 - [Finding or "Adequate coverage"]
@@ -67,12 +119,16 @@ Post reviews in this structured format:
 ## Verdict Criteria
 
 - **LGTM**: No blocking issues, code meets quality standards, ready to merge
-- **Needs Changes**: Minor issues worth addressing before merge
+- **Needs Changes**: Minor issues worth addressing before merge (including lint issues)
 - **Blocking Issues**: Security vulnerabilities, logic errors, or missing critical functionality
 
+**Note**: Lint issues alone should result in "Needs Changes" at most, never "Blocking Issues".
+Lint issues are style/formatting concerns, not functional problems.
+
 ## Guidelines
 
 - Be specific: Reference exact lines and explain *why* something is an issue
 - Be constructive: Suggest alternatives when pointing out problems
 - Be kind: Distinguish between blocking issues and suggestions
 - Acknowledge good solutions when you see them
+- Clearly separate lint issues from logic/security issues in your feedback