🧪 Fix SDK E2E tests to work with vizzly tdd run (#183)

## Summary

This PR fixes SDK E2E tests to work properly with both `vizzly tdd run`
(local TDD mode) and `vizzly run` (cloud mode), and reorganizes CI
workflows for better maintainability.

## Changes

### CI Workflow Reorganization
- Split monolithic `ci.yml` into focused workflow files:
  - `sdk-e2e.yml` - E2E tests for all SDKs (runs on every PR)
- `sdk-unit.yml` - Unit tests with matrix testing (runs when SDK files
change)
  - `reporter.yml` - Reporter UI tests
  - `tui.yml` - TUI tests
- E2E tests now run in both TDD and cloud modes for each SDK

### Ruby SDK Fixes
- Add `cloud_mode?` helper to detect when running with `VIZZLY_TOKEN`
- Add `assert_screenshot_success` helper for mode-aware assertions
- TDD mode: asserts status is `'new'` or `'match'`
- Cloud mode: asserts `success` is `true` (no local comparison happens)
- Fixed in both `integration_test.rb` and `e2e_test.rb`

### Vitest SDK Fixes
- Refactored to use shared test-site for consistency with other SDKs
- Test the actual SDK functionality (`toMatchScreenshot` matcher)
- Load test-site CSS for consistent styling
- Removed custom commands that were for full-page navigation, not SDK
testing

### All SDKs
- Detect `VIZZLY_SERVER_URL` env var to skip starting own TDD server
when running under `vizzly tdd run` or `vizzly run`
- Fix assertions to handle both TDD mode (returns `status` field) and
cloud mode (returns `success: true`)

## Test plan

- [x] All SDK E2E tests pass in TDD mode (`vizzly tdd run`)
- [x] All SDK E2E tests pass in cloud mode (`vizzly run`)
- [x] Ruby lint passes (`bundle exec rubocop`)
- [x] CI workflow YAML is valid

Author: Robdel12

.github/workflows/ci.yml

@@ -0,0 +1,51 @@
+name: Reporter Visual Tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  visual:
+    name: Visual Tests
+    runs-on: ubuntu-latest
+    timeout-minutes: 8
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Use Node.js 22
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run build
+
+      - name: Get installed Playwright version
+        id: playwright-version
+        run: echo "version=$(npx playwright --version | grep -oE '[0-9]+\.[0-9]+\.[0-9]+')" >> $GITHUB_OUTPUT
+
+      - name: Cache Playwright browsers
+        uses: actions/cache@v4
+        id: playwright-cache
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-browsers-${{ steps.playwright-version.outputs.version }}-firefox
+
+      - name: Install Playwright browsers
+        if: steps.playwright-cache.outputs.cache-hit != 'true'
+        run: npx playwright install firefox --with-deps
+
+      - name: Run reporter visual tests
+        run: npm run test:reporter:visual
+        env:
+          CI: true
+          VIZZLY_TOKEN: ${{ secrets.VIZZLY_REPORTER_TOKEN }}
+          VIZZLY_COMMIT_MESSAGE: ${{ github.event.pull_request.head.commit.message || github.event.head_commit.message }}
+          VIZZLY_COMMIT_SHA: ${{ github.event.pull_request.head.sha || github.event.head_commit.id }}