refactor: rename CLAUDE.md to AGENTS.md (#8052)

## Summary

Pure rename of CLAUDE.md files to AGENTS.md (no content changes).

## Changes

| Old Path | New Path |
|----------|----------|
| `.github/CLAUDE.md` | `.github/AGENTS.md` |
| `.storybook/CLAUDE.md` | `.storybook/AGENTS.md` |
| `browser_tests/CLAUDE.md` | `browser_tests/AGENTS.md` |
| `src/CLAUDE.md` | `src/AGENTS.md` |
| `src/components/CLAUDE.md` | `src/components/AGENTS.md` |
| `src/lib/litegraph/CLAUDE.md` | `src/lib/litegraph/AGENTS.md` |

Root `CLAUDE.md` deleted (content will be merged into `AGENTS.md` in
follow-up PR).

## Follow-up

A second PR will add glob-based guidance files and consolidate
redundancies.

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Co-authored-by: Christian Byrne <cbyrne@comfy.org>

docs/guidance/playwright.md

@@ -0,0 +1,33 @@
+---
+globs:
+  - '**/*.spec.ts'
+---
+
+# Playwright E2E Test Conventions
+
+See `docs/testing/*.md` for detailed patterns.
+
+## Best Practices
+
+- Follow [Playwright Best Practices](https://playwright.dev/docs/best-practices)
+- Do NOT use `waitForTimeout` - use Locator actions and retrying assertions
+- Prefer specific selectors (role, label, test-id)
+- Test across viewports
+
+## Test Tags
+
+Tags are respected by config:
+- `@mobile` - Mobile viewport tests
+- `@2x` - High DPI tests
+
+## Test Data
+
+- Check `browser_tests/assets/` for test data and fixtures
+- Use realistic ComfyUI workflows for E2E tests
+
+## Running Tests
+
+```bash
+pnpm test:browser                 # Run all E2E tests
+pnpm test:browser -- --ui         # Interactive UI mode
+```