feat(testing): Drive the real app with agent-browser

[charlesvien]

Problem

We want to verify and screenshot changes in the real running Electron app (live tRPC, workspace-server, real data), not just in unit or E2E specs.

Changes

1. Drive the real running app over CDP with agent-browser on :9222: snapshot the accessibility tree, click/type, and screenshot the live UI
2. Add a test-electron-app skill documenting the connect → snapshot → screenshot loop plus repo specifics (port, auth/data, dev-alongside-prod)
3. Add a pnpm app:cdp preflight (scripts/electron-cdp.mjs): validate the port, verify the app is reachable, then connect
4. Launch the dev app with --remote-debugging-port=9222
5. Drop --color-scheme dark: that global flag forces a 1280x720 viewport that blanks the Electron window and sticks in the agent-browser daemon until it restarts

How did you test this?

Manually by using itself

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit 01ba6e2.}

[greptile-apps]

Prompt To Fix All With AI

Fix the following 2 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 2
.claude/skills/screenshot-dev-app/SKILL.md:3
**`allowed-tools` pattern doesn't match `pnpm app:cdp`**

The pattern `Bash(pnpm app:cdp:*)` requires the command to begin with the literal string `pnpm app:cdp:` (colon-then-wildcard), so it covers subcommands like `pnpm app:cdp:something` but not the bare `pnpm app:cdp` invocation shown throughout the skill body. An agent following this skill will be blocked from running the preflight step. The same pattern also appears in `test-electron-app/SKILL.md`. Dropping the trailing colon — `Bash(pnpm app:cdp*)` — matches the bare command and any future variants.

### Issue 2 of 2
scripts/electron-cdp.mjs:25-30
**Spawn error other than ENOENT silently falls through**

The ENOENT guard only fires when the `agent-browser` binary can't be found. Any other `spawnSync` error (e.g. permission denied, `EACCES`) leaves `version.error` set but non-null with a different `.code`, so the check passes and execution continues to `version.stdout.trim()`. With `encoding: "utf8"` set, `stdout` will be an empty string rather than null, so it won't crash — but the success banner will read `✓ agent-browser ` with no version, and the script will proceed to the CDP check against an unusable binary. Consider broadening the guard to `version.error` (any error) to give a clear failure message.

_{Reviews (1): Last reviewed commit: "restore screenshot skill via agent-brows..." | Re-trigger Greptile}

[stamphog]

Gates denied this PR: it touches dependency/toolchain files (package.json changes) and exceeds the size threshold for auto-review. This needs a human reviewer.

[stamphog]

Gates denied this PR: it touches dependency/toolchain files (package.json changes) and is classified as a cross-cutting feature too large for auto-approval. This requires a human reviewer.