Fix instrument ID editing accordion collapse issue with UUID-based tracking

Implemented stable UUID-based accordion tracking to allow editing the
instrument ID field without form collapsing or losing focus.

Changes:
- Added internal _uuid field to Device interface for stable UI tracking
- Implemented deterministic UUID generation based on device ID hash
- Changed accordion expansion tracking from device ID to UUID
- Fixed E2E test config mock to return JSON instead of YAML
- Enhanced E2E fixture modal dismissal with multiple fallback strategies

This ensures:
- Users can freely edit the ID field without accordion closing
- Instrument panel expansion state persists across page reloads
- E2E tests can properly load config and test add instrument flow

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

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

Author: MarkoVcode

benchmesh-serial-service/frontend/e2e/fixtures/base.ts

@@ -15,6 +15,47 @@ export const test = base.extend<{ mockPage: Page }>({
     // Navigate to the app
     await page.goto('/ui/');
 
+    // Wait for activity bar to render (which requires instruments to be loaded)
+    await page.waitForSelector('[data-testid="activity-bar"]', { timeout: 10000 });
+
+    // Wait for instrument items to appear in activity bar
+    // We have 2 mock instruments, so there should be activity bar items
+    await page.waitForSelector('.activity-bar__instruments .activity-bar-item', { timeout: 5000 });
+
+    // Explicitly dismiss any tutorial tooltips or modals that might be open
+    try {
+      const modalOverlay = page.locator('.modal-overlay');
+      const isModalVisible = await modalOverlay.isVisible().catch(() => false);
+
+      if (isModalVisible) {
+        // Try to find and click "Got it" button first
+        const gotItButton = page.locator('button:has-text("Got it"), button:has-text("OK")');
+        const isButtonVisible = await gotItButton.isVisible().catch(() => false);
+
+        if (isButtonVisible) {
+          await gotItButton.click({ timeout: 1000 });
+        } else {
+          // Force close by clicking overlay
+          await modalOverlay.click({ force: true, position: { x: 5, y: 5 } });
+        }
+
+        // Wait for modal to be completely hidden
+        await page.waitForSelector('.modal-overlay', { state: 'hidden', timeout: 3000 }).catch(() => {
+          // If it doesn't hide, try removing it with JavaScript as last resort
+          page.evaluate(() => {
+            const overlay = document.querySelector('.modal-overlay');
+            if (overlay) overlay.remove();
+          });
+        });
+      }
+    } catch (e) {
+      // If anything fails, log but don't fail the test setup
+      console.log('Note: Could not dismiss modal overlay:', e);
+    }
+
+    // Give time for UI to stabilize
+    await page.waitForTimeout(500);
+
     // Use the configured page
     await use(page);
   },

benchmesh-serial-service/frontend/e2e/utils/api-mock.ts

@@ -106,28 +106,35 @@ export async function setupApiMocks(page: Page) {
   // Mock config endpoint
   await page.route('**/config', async (route: Route) => {
     if (route.request().method() === 'GET') {
-      // Return YAML format as expected by the backend
-      const yamlConfig = `version: 1
-devices:
-  - id: test-psu-1
-    name: "TENMA PSU"
-    driver: tenma_72
-    port: /dev/ttyUSB0
-    baud: 9600
-    serial: 8N1
-    model: 72-2540
-  - id: test-dmm-1
-    name: "OWON DMM"
-    driver: owon_xdm
-    port: /dev/ttyUSB1
-    baud: 115200
-    serial: 8N1
-    model: XDM1041`;
+      // Return JSON format for frontend consumption
+      const config = {
+        version: 1,
+        devices: [
+          {
+            id: 'test-psu-1',
+            name: 'TENMA PSU',
+            driver: 'tenma_72',
+            port: '/dev/ttyUSB0',
+            baud: 9600,
+            serial: '8N1',
+            model: '72-2540'
+          },
+          {
+            id: 'test-dmm-1',
+            name: 'OWON DMM',
+            driver: 'owon_xdm',
+            port: '/dev/ttyUSB1',
+            baud: 115200,
+            serial: '8N1',
+            model: 'XDM1041'
+          }
+        ]
+      };
 
       await route.fulfill({
         status: 200,
-        contentType: 'text/plain',
-        body: yamlConfig
+        contentType: 'application/json',
+        body: JSON.stringify(config)
       });
     } else {
       await route.fulfill({
@@ -190,6 +197,83 @@ devices:
       body: JSON.stringify([])
     });
   });
+
+  // Mock drivers endpoint
+  await page.route('**/drivers', async (route: Route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify({
+        'tenma_72': {
+          vendor: 'TENMA',
+          family: '72-Series',
+          supported_transports: ['serial']
+        },
+        'owon_xdm': {
+          vendor: 'OWON',
+          family: 'XDM',
+          supported_transports: ['serial', 'usbtmc']
+        }
+      })
+    });
+  });
+
+  // Mock drivers/:driver/models endpoint
+  await page.route('**/drivers/*/models', async (route: Route) => {
+    const url = route.request().url();
+    if (url.includes('tenma_72')) {
+      await route.fulfill({
+        status: 200,
+        contentType: 'application/json',
+        body: JSON.stringify(['72-2540', '72-2545', '72-2550'])
+      });
+    } else if (url.includes('owon_xdm')) {
+      await route.fulfill({
+        status: 200,
+        contentType: 'application/json',
+        body: JSON.stringify(['XDM1041', 'XDM1241'])
+      });
+    } else {
+      await route.fulfill({
+        status: 200,
+        contentType: 'application/json',
+        body: JSON.stringify([])
+      });
+    }
+  });
+
+  // Mock ports endpoint (serial ports)
+  await page.route('**/ports', async (route: Route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify([
+        {
+          device: '/dev/ttyUSB0',
+          description: 'USB Serial Port 0',
+          manufacturer: 'FTDI',
+          serial_number: '12345',
+          hwid: 'USB VID:PID=0403:6001'
+        },
+        {
+          device: '/dev/ttyUSB1',
+          description: 'USB Serial Port 1',
+          manufacturer: 'CH340',
+          serial_number: '67890',
+          hwid: 'USB VID:PID=1a86:7523'
+        }
+      ])
+    });
+  });
+
+  // Mock USB TMC devices endpoint
+  await page.route('**/usbtmc/devices', async (route: Route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify([])
+    });
+  });
 }
 
 /**