Add GenericOWONPSU component with voltage/current limit controls

- Create GenericOWONPSU component based on GenericPSU
- Add voltage_limit and current_limit editable fields in Settings section
- Implement API endpoints for reading/setting limits:
  - GET/POST /instruments/{class}/{device}/{channel}/voltage_limit
  - GET/POST /instruments/{class}/{device}/{channel}/current_limit
- Register GenericOWONPSU in ClassPods for InstrumentPod rendering
- Follow same 5-digit display pattern as V/A settings
- Include SET buttons and API tooltips for limits

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: MarkoVcode

.github/workflows/e2e-tests.yml

@@ -0,0 +1,59 @@
+name: E2E Tests
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  workflow_dispatch:
+
+jobs:
+  e2e-tests:
+    name: Playwright E2E Tests
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+
+    defaults:
+      run:
+        working-directory: benchmesh-serial-service/frontend
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '18'
+          cache: 'npm'
+          cache-dependency-path: benchmesh-serial-service/frontend/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Install Playwright browsers
+        run: npx playwright install --with-deps chromium
+
+      - name: Build frontend
+        run: npm run build
+
+      - name: Run Playwright tests
+        run: npm run test:e2e
+        env:
+          CI: true
+
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: playwright-report
+          path: benchmesh-serial-service/frontend/playwright-report/
+          retention-days: 30
+
+      - name: Upload test videos
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: playwright-videos
+          path: benchmesh-serial-service/frontend/test-results/
+          retention-days: 7

CLAUDE.md

@@ -187,12 +187,17 @@ Both systems coexist without interference and provide complementary insights.
 # From repository root - starts everything (API, Frontend, Node-RED)
 ./start.sh
 
+# Start with frontend UI build (use when frontend code has changed)
+./start.sh --uibuild
+
 # Services will be available at:
-# - Frontend: http://localhost:57666
+# - Frontend: http://localhost:57666/ui
 # - API Docs: http://localhost:57666/docs
 # - Node-RED: http://localhost:1880
 ```
 
+**Note**: The `--uibuild` flag triggers a full frontend build before starting services. This runs `npm ci` and `npm run build` in the frontend directory. Use this flag when you've made changes to the frontend code. Without the flag, the script uses the existing build in `dist/`.
+
 ### Backend Development
 
 ```bash
@@ -249,13 +254,34 @@ npm run build
 # Preview production build
 npm run preview
 
-# Run tests
+# Run unit tests (vitest)
 npm test
 
-# Run tests once (CI mode)
+# Run unit tests once (CI mode)
 npm run test:run
+
+# Run E2E tests (Playwright)
+npm run test:e2e
+
+# Run E2E tests with UI mode
+npm run test:e2e:ui
+
+# Run E2E tests in headed mode (visible browser)
+npm run test:e2e:headed
+
+# Run E2E tests in debug mode
+npm run test:e2e:debug
 ```
 
+**E2E Testing**: The frontend includes comprehensive Playwright tests that verify UI functionality with mocked API and WebSocket connections. Tests cover:
+- App navigation and modals (Configuration, Documentation, Metrics, Recording)
+- Instrument display and status indicators
+- Device interaction and real-time updates
+- API integration, error handling, and retry logic
+- WebSocket connection and data streaming
+
+See `benchmesh-serial-service/frontend/e2e/README.md` for detailed E2E testing documentation.
+
 ### Driver CLI Tool
 
 Test driver methods directly from command line:
@@ -306,12 +332,29 @@ python3 mcp_services/testing/client_helper.py
 
 The MCP service provides:
 - **Backend Tests**: Run pytest tests with filtering (46 tests discovered)
-- **Frontend Tests**: Run vitest tests (21 tests discovered)
+- **Frontend Unit Tests**: Run vitest tests (21 tests discovered)
+- **E2E Tests**: Run Playwright tests for UI integration testing (31 tests)
 - **Integration Tests**: Run integration tests separately
 - **Smart Testing**: Automatically run tests for changed files
 - **Test Discovery**: Find all available tests
 - **JSON Reports**: Structured test results with detailed metrics
 
+### E2E Testing Modes
+
+**Mocked Tests (default)**: Fast, isolated tests with mocked API/WebSocket
+```bash
+npm run test:e2e
+```
+
+**Real Service Tests**: Full integration tests against running backend
+```bash
+# 1. Start backend service
+cd benchmesh-serial-service && PYTHONPATH=src uvicorn benchmesh_service.api:app --port 57666 &
+
+# 2. Run E2E tests with real service
+npm run test:e2e:service
+```
+
 ### Usage Examples
 
 ```python

benchmesh-serial-service/frontend/.gitignore

@@ -0,0 +1,4 @@
+# Playwright
+test-results/
+playwright-report/
+playwright/.cache/