feat: add LintTool and UnitTestTool for code quality

[LifeJiggy]

Summary

• what changed: Added LintTool and UnitTestTool for code quality. LintTool runs linters (eslint, prettier, ruff, golangci-lint, shellcheck). UnitTestTool runs unit tests (jest, pytest, vitest, go test, cargo test). Both auto-detect tool from config files.
• why it changed: Developers need to check code quality and run tests while working in Claude. Instead of switching to terminal, they can run these commands directly with proper security validation.

Impact

• user-facing impact: Users can run linters and unit tests directly in Claude. Supports auto-detection of tools from config files. Permission prompts for potentially destructive operations.
• developer/maintainer impact: Two new tools add to codebase with input validation per tool type for security.

Testing

• bun run build
• bun run smoke
• focused tests: bun test src/tools/LintTool/ src/tools/UnitTestTool/ (25 pass)

Notes

• provider/model path tested: N/A
• screenshots attached (if UI changed): N/A
• follow-up work or known limitations: Could add more linters/test runners

[jatmn]

Findings

• [P1] Register the new tools so the model can call them
  src/tools.ts:183
  The PR adds LintTool and UnitTestTool, but src/tools.ts never imports them or includes them in getAllBaseTools(). Because the built-in tool pool is assembled from this list, neither Lint nor UnitTest is exposed to the model in normal CLI/SDK execution, so the advertised user-facing feature is currently unreachable. Please wire both tools into the tool registry (and any relevant presets/filtering surfaces) and add coverage that getTools() includes them.

• [P2] Use the parent directory as cwd for existing file targets
  src/tools/LintTool/LintTool.ts:134
  The working directory fallback only uses dirname(targetPath) when the target looks like a file and does not exist. For the common case where the user asks to lint or test an existing file, workingDir becomes the file path itself, so spawnSync(..., { cwd: workingDir }) fails before the linter/test runner can run. The same pattern exists in src/tools/UnitTestTool/UnitTestTool.ts:95. Please treat existing file paths as file targets too, and keep cwd on the containing directory while passing the file path as the command argument.

[gnanam1990]

Thanks for this — built-in lint and test tooling is a nice quality-of-life addition, and the prompt structure is well thought out.

I reviewed it independently alongside @jatmn's feedback, and his findings are accurate: neither LintTool nor UnitTestTool is imported into src/tools.ts / getAllBaseTools(), so the feature isn't reachable as it stands, and the workingDir fallback in LintTool.ts:134 / UnitTestTool.ts:95 resolves to the file path itself for an existing-file target, which fails when passed as spawnSync's cwd (it must be a directory).

Once those are sorted, the next review will also want to look at command-execution and sandboxing safety and permission gating for tools that spawnSync external runners, and whether the two tools are better split into separate PRs for easier review. Flagging now so this doesn't sit idle waiting on us — the ball's with you, and happy to re-review promptly once it's updated.