fix(adsb): fix aircraft photo display and add Drone Intelligence docs

- Fix stale DOM refs in fetchAircraftPhoto: elements were captured before
  await fetch(), but showAircraftDetails rebuilds innerHTML on every RAF
  update, leaving the async path writing to detached nodes. Now re-queries
  the DOM after await, and the cache (synchronous) path queries inline so
  refs are always fresh.
- Add thumbnail fallback in aircraft_photo route: fall back to thumbnail
  when thumbnail_large.src is absent rather than returning null.
- Add Drone Intelligence to nav, help modal, cheat sheets, README, and docs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

static/js/core/cheat-sheets.js

@@ -17,12 +17,13 @@ const CheatSheets = (function () {
         sstv:        { title: 'ISS SSTV',                icon: '🖼️', hardware: 'RTL-SDR + 145MHz antenna',               description: 'Receives ISS SSTV images via slowrx.',                                    whatToExpect: 'Color images during ISS SSTV events (PD180 mode).',             tips: ['ISS SSTV: 145.800 MHz', 'Check ARISS for active event dates', 'ISS must be overhead — check pass times'] },
         weathersat:  { title: 'Weather Satellites',      icon: '🌤️', hardware: 'RTL-SDR + 137MHz turnstile/QFH antenna',  description: 'Decodes NOAA APT and Meteor LRPT weather imagery via SatDump.',          whatToExpect: 'Infrared/visible cloud imagery.',                              tips: ['NOAA 15/18/19: 137.1–137.9 MHz APT', 'Meteor M2-3: 137.9 MHz LRPT', 'Use circular polarized antenna (QFH or turnstile)'] },
         sstv_general:{ title: 'HF SSTV',                 icon: '📷', hardware: 'RTL-SDR + HF upconverter',                description: 'Receives HF SSTV transmissions.',                                          whatToExpect: 'Amateur radio images on 14.230 MHz (USB mode).',                tips: ['14.230 MHz USB is primary HF SSTV frequency', 'Scottie 1 and Martin 1 most common', 'Best during daylight hours'] },
-        gps:         { title: 'GPS Receiver',            icon: '🗺️', hardware: 'USB GPS receiver (NMEA)',                 description: 'Streams GPS position and feeds location to other modes.',                  whatToExpect: 'Lat/lon, altitude, speed, heading, satellite count.',          tips: ['BT Locate uses GPS for trail logging', 'Set observer location for satellite prediction', 'Verify a 3D fix before relying on altitude'] },
-        spaceweather:{ title: 'Space Weather',           icon: '☀️', hardware: 'None (NOAA/SpaceWeatherLive data)',        description: 'Monitors solar activity and geomagnetic storm indices.',                   whatToExpect: 'Kp index, solar flux, X-ray flare alerts, CME tracking.',      tips: ['High Kp (≥5) = geomagnetic storm', 'X-class flares cause HF radio blackouts', 'Check before HF or satellite operations'] },
-        controller_monitor: { title: 'Controller Monitor', icon: '🖧', hardware: 'Optional remote agents',               description: 'Aggregated controller view across connected agents and local sources.',    whatToExpect: 'Combined device activity, logs, and agent health in one place.', tips: ['Use it to compare what each agent is seeing', 'Check agent status before remote starts', 'Open Manage to add or troubleshoot agents'] },
-        tscm:        { title: 'TSCM Counter-Surveillance', icon: '🔍', hardware: 'WiFi + Bluetooth adapters',             description: 'Technical Surveillance Countermeasures — detects hidden devices.',        whatToExpect: 'RF baseline comparison, rogue device alerts, tracker detection.', tips: ['Take baseline in a known-clean environment', 'New strong signals = potential bug', 'Correlate WiFi + Bluetooth observations'] },
+        gps:         { title: 'GPS Receiver',            icon: '🗺️', hardware: 'USB GPS receiver (NMEA)',                 description: 'Streams GPS position and feeds location to other modes.',                  whatToExpect: 'Lat/lon, altitude, speed, heading, satellite count.',          tips: ['BT Locate uses GPS for trail logging', 'Set observer location for satellite prediction', 'Verify a 3D fix before relying on altitude'] },
+        spaceweather:{ title: 'Space Weather',           icon: '☀️', hardware: 'None (NOAA/SpaceWeatherLive data)',        description: 'Monitors solar activity and geomagnetic storm indices.',                   whatToExpect: 'Kp index, solar flux, X-ray flare alerts, CME tracking.',      tips: ['High Kp (≥5) = geomagnetic storm', 'X-class flares cause HF radio blackouts', 'Check before HF or satellite operations'] },
+        controller_monitor: { title: 'Controller Monitor', icon: '🖧', hardware: 'Optional remote agents',               description: 'Aggregated controller view across connected agents and local sources.',    whatToExpect: 'Combined device activity, logs, and agent health in one place.', tips: ['Use it to compare what each agent is seeing', 'Check agent status before remote starts', 'Open Manage to add or troubleshoot agents'] },
+        tscm:        { title: 'TSCM Counter-Surveillance', icon: '🔍', hardware: 'WiFi + Bluetooth adapters',             description: 'Technical Surveillance Countermeasures — detects hidden devices.',        whatToExpect: 'RF baseline comparison, rogue device alerts, tracker detection.', tips: ['Take baseline in a known-clean environment', 'New strong signals = potential bug', 'Correlate WiFi + Bluetooth observations'] },
         spystations: { title: 'Spy Stations',            icon: '🕵️', hardware: 'RTL-SDR + HF antenna',                   description: 'Database of known number stations, military, and diplomatic HF signals.', whatToExpect: 'Scheduled broadcasts, frequency database, tune-to links.',    tips: ['Numbers stations often broadcast on the hour', 'Use Spectrum Waterfall to tune directly', 'STANAG and HF mil signals are common'] },
         websdr:      { title: 'WebSDR',                  icon: '🌐', hardware: 'None (uses remote SDR servers)',           description: 'Access remote WebSDR receivers worldwide for HF shortwave listening.', whatToExpect: 'Live audio from global HF receivers, waterfall display.',      tips: ['websdr.org lists available servers', 'Good for HF when local antenna is lacking', 'Use in-app player for seamless experience'] },
+        drone:       { title: 'Drone Intelligence',      icon: '🚁', hardware: 'WiFi adapter (monitor mode) + RTL-SDR + optional HackRF', description: 'Multi-vector UAV detection: ASTM F3411 Remote ID (WiFi/BLE), RTL-SDR 433/868 MHz RF fingerprinting, HackRF 2.4/5.8 GHz.', whatToExpect: 'Drone contacts with ID, operator, GPS position (if broadcast), detection vectors, and risk level.', tips: ['Remote ID is mandatory in the US/EU since 2023 — absence flags high risk', 'RTL-SDR catches DJI/FPV video links on 2.4 GHz if HackRF unavailable', 'Risk HIGH = no Remote ID or non-compliant; MEDIUM = multi-vector or RSSI anomaly', 'Map markers appear only for contacts with GPS coordinates from Remote ID'] },
         subghz:      { title: 'SubGHz Transceiver',      icon: '📡', hardware: 'HackRF One',                             description: 'Transmit and receive sub-GHz RF signals for IoT and industrial protocols.', whatToExpect: 'Raw signal capture, replay, and protocol analysis.',        tips: ['Only use on licensed frequencies', 'Capture mode records raw IQ for replay', 'Common: garage doors, keyfobs, 315/433/868/915 MHz'] },
         rtlamr:      { title: 'Utility Meter Reader',    icon: '⚡', hardware: 'RTL-SDR dongle',                          description: 'Reads AMI/AMR smart utility meter broadcasts via rtlamr.',                whatToExpect: 'Meter IDs, consumption readings, interval data.',               tips: ['Most meters broadcast on 915 MHz', 'MSG types 5, 7, 13, 21 most common', 'Consumption data is read-only public broadcast'] },
         waterfall:   { title: 'Spectrum Waterfall',      icon: '🌊', hardware: 'RTL-SDR or HackRF (WebSocket)',           description: 'Full-screen real-time FFT spectrum waterfall display.',                  whatToExpect: 'Color-coded signal intensity scrolling over time.',             tips: ['Turbo palette has best contrast for weak signals', 'Peak hold shows max power in red', 'Hover over waterfall to see frequency'] },