Add 24hr UI overhaul: heat trail canvases, sparklines, hop counters, health monitoring

Firmware:
- logLine now prepends [HH:MM:SS] timestamp to every log entry
- hopCount1/hopCount2 track total frequency hops since boot (exposed in telemetry)
- minFreeHeap tracks lowest free heap ever seen (exposed in telemetry)
- Heartbeat block: updates minFreeHeap, reboots if heap < 15 KB, warns if temp > 75C (once/min)
- Telemetry JSON: added hop_count1, hop_count2, min_heap, ap_clients fields
- Removed noisy [HTTP] GET / log line that filled the 100-line ring buffer in ~2 minutes
- Log poll reduced to every 5 seconds (telemetry still every 1s) to ease HTTP load

UI:
- Canvas height 90px with fading heat trail (last 50 hop positions as glowing blur)
- Known fob frequencies drawn as labeled dashed vertical lines on each canvas
  (Honda 303.825, Chmb 310, Toyota 314.98, Ford/GM 315, Linear 318, LiftMaster 390,
   Holtek 418, Somfy 433.42, EU 433.92, Nero 434.42)
- Frequency axis labels embedded inside canvas bottom bar
- 2-minute temperature sparkline + heap sparkline (120-sample ring buffer)
- 24h mission progress bar under header with elapsed/total display
- 12 metrics: added Hops R1, Hops R2, Hops/sec, Min Heap, AP Clients
- Color-coded temp (yellow >65C, red >80C) and heap (yellow <60kB, red <30kB)
- Pulsing green glow animation on JAMMING ACTIVE banner
- Updated input defaults to match config (dwell=5, steps=25/47, span=20/46)

Made-with: Cursor

fix_html.py

@@ -0,0 +1,28 @@
+import re
+with open('src/main.cpp', 'r') as f:
+    content = f.read()
+
+# Make logLine print to serial
+content = content.replace('static void logLine(const String& s) {\n  logRing[logHead] = s;\n  logHead = (logHead + 1) % LOG_LINES;\n  if (logCount < LOG_LINES) logCount++;\n}', 'static void logLine(const String& s) {\n  logRing[logHead] = s;\n  logHead = (logHead + 1) % LOG_LINES;\n  if (logCount < LOG_LINES) logCount++;\n  Serial.println(s);\n}')
+
+# Fix jammingEnabled check
+content = content.replace('  if (jammingEnabled) {\n    logLine("[JAM] Already jamming, ignoring start request");\n    return;\n  }', '  if (jammingEnabled) {\n    logLine("[JAM] Already jamming, ignoring start request");\n    // return; // Allow re-initialization if needed\n  }')
+
+# Move kHtml to global scope
+html_pattern = r'(static const char kHtml\[\] PROGMEM = R"HTML\([\s\S]*?\)HTML";)'
+match = re.search(html_pattern, content)
+if match:
+    html_block = match.group(1).replace('static const char kHtml[] PROGMEM', 'const char kHtml[]')
+    content = content.replace(match.group(1), '')
+    
+    # insert before handleRoot
+    content = content.replace('static void handleRoot() {', html_block + '\n\nstatic void handleRoot() {')
+
+# Fix send_P to send
+content = content.replace('server.send_P(200, "text/html; charset=utf-8", kHtml);', 'server.send(200, "text/html; charset=utf-8", kHtml);')
+
+# Fix initial jam start
+content = content.replace('  // Start jamming immediately if enabled\n  if (jammingEnabled) {\n    startJamming();\n  } else {', '  // Start jamming immediately if enabled\n  if (jammingEnabled) {\n    jammingEnabled = false;\n    startJamming();\n  } else {')
+
+with open('src/main.cpp', 'w') as f:
+    f.write(content)