feat(ui): add signal and network tests to self-test

Add two more tests to the modem self-test:
- Test 3: Signal Strength (AT+CSQ) with quality thresholds
- Test 4: Network Connection (AT+COPS?) with operator name lookup
Respects 1 second delay between each AT command.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

html/saraR4.html

@@ -392,6 +392,24 @@
                     </div>
                     <span id="test_sim_status" class="badge bg-secondary">Pending</span>
                   </div>
+
+                  <!-- Test 3: Signal Strength -->
+                  <div class="list-group-item d-flex justify-content-between align-items-center" id="test_signal">
+                    <div>
+                      <strong>Signal Strength</strong>
+                      <div class="small text-muted" id="test_signal_detail">Waiting...</div>
+                    </div>
+                    <span id="test_signal_status" class="badge bg-secondary">Pending</span>
+                  </div>
+
+                  <!-- Test 4: Network Connection -->
+                  <div class="list-group-item d-flex justify-content-between align-items-center" id="test_network">
+                    <div>
+                      <strong>Network Connection</strong>
+                      <div class="small text-muted" id="test_network_detail">Waiting...</div>
+                    </div>
+                    <span id="test_network_status" class="badge bg-secondary">Pending</span>
+                  </div>
                 </div>
 
                 <!-- Logs section -->
@@ -1501,6 +1519,14 @@ function resetSelfTestUI() {
   document.getElementById('test_sim_status').textContent = 'Pending';
   document.getElementById('test_sim_detail').textContent = 'Waiting...';
 
+  document.getElementById('test_signal_status').className = 'badge bg-secondary';
+  document.getElementById('test_signal_status').textContent = 'Pending';
+  document.getElementById('test_signal_detail').textContent = 'Waiting...';
+
+  document.getElementById('test_network_status').className = 'badge bg-secondary';
+  document.getElementById('test_network_status').textContent = 'Pending';
+  document.getElementById('test_network_detail').textContent = 'Waiting...';
+
   // Reset logs
   document.getElementById('selftest_logs').innerHTML = '';
 
@@ -1656,6 +1682,117 @@ async function selfTestSequence() {
       testsFailed++;
     }
 
+    // Delay between AT commands
+    await delay(1000);
+
+    // Step 4: Test Signal Strength (AT+CSQ)
+    document.getElementById('selftest_status').innerHTML = `
+      <div class="d-flex align-items-center text-primary">
+        <div class="spinner-border spinner-border-sm me-2" role="status"></div>
+        <span>Testing signal strength...</span>
+      </div>`;
+
+    updateTestStatus('signal', 'Testing...', 'Sending AT+CSQ command...', 'bg-info');
+
+    try {
+      const signalResponse = await sendATCommand('AT+CSQ', 5);
+
+      const csqMatch = signalResponse.match(/\+CSQ:\s*(\d+),(\d+)/);
+      if (signalResponse.includes('OK') && csqMatch) {
+        const signalPower = parseInt(csqMatch[1]);
+        const qual = parseInt(csqMatch[2]);
+
+        if (signalPower === 99) {
+          updateTestStatus('signal', 'Failed', 'No signal detected', 'bg-danger');
+          testsFailed++;
+        } else if (signalPower === 0) {
+          updateTestStatus('signal', 'Warning', 'Very poor signal (0/31)', 'bg-warning');
+          testsFailed++;
+        } else if (signalPower <= 24) {
+          updateTestStatus('signal', 'Passed', `Poor signal (${signalPower}/31)`, 'bg-success');
+          testsPassed++;
+        } else if (signalPower <= 26) {
+          updateTestStatus('signal', 'Passed', `Good signal (${signalPower}/31)`, 'bg-success');
+          testsPassed++;
+        } else if (signalPower <= 28) {
+          updateTestStatus('signal', 'Passed', `Very good signal (${signalPower}/31)`, 'bg-success');
+          testsPassed++;
+        } else {
+          updateTestStatus('signal', 'Passed', `Excellent signal (${signalPower}/31)`, 'bg-success');
+          testsPassed++;
+        }
+      } else if (signalResponse.includes('ERROR')) {
+        updateTestStatus('signal', 'Failed', 'Unable to read signal', 'bg-danger');
+        testsFailed++;
+      } else {
+        updateTestStatus('signal', 'Warning', 'Unexpected response', 'bg-warning');
+        testsFailed++;
+      }
+    } catch (error) {
+      updateTestStatus('signal', 'Failed', error.message, 'bg-danger');
+      testsFailed++;
+    }
+
+    // Delay between AT commands
+    await delay(1000);
+
+    // Step 5: Test Network Connection (AT+COPS?)
+    document.getElementById('selftest_status').innerHTML = `
+      <div class="d-flex align-items-center text-primary">
+        <div class="spinner-border spinner-border-sm me-2" role="status"></div>
+        <span>Testing network connection...</span>
+      </div>`;
+
+    updateTestStatus('network', 'Testing...', 'Sending AT+COPS? command...', 'bg-info');
+
+    try {
+      // Load operators data for network name lookup
+      let opData = null;
+      try {
+        opData = await loadOperatorsData();
+      } catch (e) {
+        addSelfTestLog('Warning: Could not load operators data');
+      }
+
+      const networkResponse = await sendATCommand('AT+COPS?', 5);
+
+      const copsMatch = networkResponse.match(/\+COPS:\s*(\d+)(?:,(\d+),"?([^",]+)"?,(\d+))?/);
+      if (networkResponse.includes('OK') && copsMatch) {
+        const mode = copsMatch[1];
+        const oper = copsMatch[3];
+        const act = copsMatch[4];
+
+        if (oper) {
+          // Get operator name from lookup table
+          let operatorName = oper;
+          if (opData && opData.operators && opData.operators[oper]) {
+            operatorName = opData.operators[oper].name;
+          }
+
+          // Get access technology
+          let actDesc = 'Unknown';
+          if (opData && opData.accessTechnology && opData.accessTechnology[act]) {
+            actDesc = opData.accessTechnology[act];
+          }
+
+          updateTestStatus('network', 'Passed', `${operatorName} (${actDesc})`, 'bg-success');
+          testsPassed++;
+        } else {
+          updateTestStatus('network', 'Warning', 'Not registered to network', 'bg-warning');
+          testsFailed++;
+        }
+      } else if (networkResponse.includes('ERROR')) {
+        updateTestStatus('network', 'Failed', 'Unable to get network info', 'bg-danger');
+        testsFailed++;
+      } else {
+        updateTestStatus('network', 'Warning', 'Unexpected response', 'bg-warning');
+        testsFailed++;
+      }
+    } catch (error) {
+      updateTestStatus('network', 'Failed', error.message, 'bg-danger');
+      testsFailed++;
+    }
+
   } catch (error) {
     addSelfTestLog(`Test sequence error: ${error.message}`);
   } finally {