feat: Weather satellite and ADS-B trail rendering improvements

Weather Satellite:
- Fix duplicate event listeners on mode re-entry via locationListenersAttached guard
- Add suspend() to stop countdown/SSE stream when switching away from the mode
- Call WeatherSat.suspend() in switchMode() when leaving weathersat
- Fix toggleScheduler() to take the checkbox element as source of truth,
  preventing both checkboxes fighting each other
- Reset isRunning/UI state after auto-capture completes (scheduler path)
- Always re-select first pass and reset selectedPassIndex after loadPasses()
- Keep timeline cursor in sync inside selectPass()
- Add seconds to pass ID format to avoid collisions on concurrent passes
- Improve predict_passes() comment clarity; fix trajectory comment

ADS-B dashboard:
- Batch altitude-colour trail segments into runs of same-colour polylines,
  reducing Leaflet layer count from O(trail length) to O(colour changes)
  for significantly better rendering performance with many aircraft

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

static/js/modes/weather-satellite.js

@@ -22,6 +22,7 @@ const WeatherSat = (function() {
     let currentPhase = 'idle';
     let consoleAutoHideTimer = null;
     let currentModalFilename = null;
+    let locationListenersAttached = false;
 
     /**
      * Initialize the Weather Satellite mode
@@ -54,8 +55,13 @@ const WeatherSat = (function() {
         if (latInput && storedLat) latInput.value = storedLat;
         if (lonInput && storedLon) lonInput.value = storedLon;
 
+        // Only attach listeners once — re-calling init() on mode switch must not
+        // accumulate duplicate listeners that fire loadPasses() multiple times.
+        if (!locationListenersAttached) {
             if (latInput) latInput.addEventListener('change', saveLocationFromInputs);
             if (lonInput) lonInput.addEventListener('change', saveLocationFromInputs);
+            locationListenersAttached = true;
+        }
     }
 
     /**
@@ -428,8 +434,17 @@ const WeatherSat = (function() {
             updateStatusUI('capturing', `Auto: ${p.name || p.satellite} ${p.frequency} MHz`);
             showNotification('Weather Sat', `Auto-capture started: ${p.name || p.satellite}`);
         } else if (data.type === 'schedule_capture_complete') {
-            showNotification('Weather Sat', `Auto-capture complete: ${(data.pass || {}).name || ''}`);
+            const p = data.pass || {};
+            showNotification('Weather Sat', `Auto-capture complete: ${p.name || ''}`);
+            // Reset UI — the decoder's stop() doesn't emit a progress complete event
+            // when called internally by the scheduler, so we handle it here.
+            isRunning = false;
+            updateStatusUI('idle', 'Auto-capture complete');
+            const captureStatus = document.getElementById('wxsatCaptureStatus');
+            if (captureStatus) captureStatus.classList.remove('active');
+            updatePhaseIndicator('complete');
             loadImages();
+            loadPasses();
         } else if (data.type === 'schedule_capture_skipped') {
             const reason = data.reason || 'unknown';
             const p = data.pass || {};
@@ -474,11 +489,13 @@ const WeatherSat = (function() {
 
             if (data.status === 'ok') {
                 passes = data.passes || [];
+                selectedPassIndex = -1;
                 renderPasses(passes);
                 renderTimeline(passes);
                 updateCountdownFromPasses();
-                // Auto-select first pass
-                if (passes.length > 0 && selectedPassIndex < 0) {
+                // Always select the first upcoming pass so the polar plot
+                // and ground track reflect the current list after every refresh.
+                if (passes.length > 0) {
                     selectPass(0);
                 }
             }
@@ -875,6 +892,9 @@ const WeatherSat = (function() {
                 b.classList.toggle('active', isActive);
             });
         }
+
+        // Keep timeline cursor in sync
+        updateTimelineCursor();
     }
 
     // ========================
@@ -939,12 +959,13 @@ const WeatherSat = (function() {
     /**
      * Toggle auto-scheduler
      */
-    async function toggleScheduler() {
+    async function toggleScheduler(source) {
+        const checked = source?.checked ?? false;
+
         const stripCheckbox = document.getElementById('wxsatAutoSchedule');
         const sidebarCheckbox = document.getElementById('wxsatSidebarAutoSchedule');
-        const checked = stripCheckbox?.checked || sidebarCheckbox?.checked;
 
-        // Sync both checkboxes
+        // Sync both checkboxes to the source of truth
         if (stripCheckbox) stripCheckbox.checked = checked;
         if (sidebarCheckbox) sidebarCheckbox.checked = checked;
 
@@ -1386,9 +1407,29 @@ const WeatherSat = (function() {
         }
     }
 
+    /**
+     * Suspend background activity when leaving the mode.
+     * Closes the SSE stream and stops the countdown interval so they don't
+     * keep running while another mode is active.  The stream is re-opened
+     * by init() or startStream() when the mode is next entered.
+     */
+    function suspend() {
+        if (countdownInterval) {
+            clearInterval(countdownInterval);
+            countdownInterval = null;
+        }
+        // Only close the stream if nothing is actively capturing/scheduling —
+        // if a capture or scheduler is running we want it to continue on the
+        // server and the stream will reconnect on next init().
+        if (!isRunning && !schedulerEnabled) {
+            stopStream();
+        }
+    }
+
     // Public API
     return {
         init,
+        suspend,
         start,
         stop,
         startPass,

templates/adsb_dashboard.html

@@ -1345,21 +1345,41 @@ ACARS: ${r.statistics.acarsMessages} messages`;
             }
             trailLines[icao] = [];
 
-            // Create gradient segments
+            // Group consecutive same-altitude-color points into single polylines.
+            // This reduces layer count from O(trail length) to O(color band changes),
+            // which is typically 1-2 polylines per aircraft instead of up to 99.
             const now = Date.now();
-            for (let i = 1; i < trail.length; i++) {
-                const p1 = trail[i-1];
-                const p2 = trail[i];
-                const age = (now - p2.time) / 1000;  // seconds
-                const opacity = Math.max(0.2, 1 - (age / 120));  // Fade over 2 minutes
+            let runColor = getAltitudeColor(trail[0].alt);
+            let runPoints = [[trail[0].lat, trail[0].lon]];
+            let runEndTime = trail[0].time;
 
-                const color = getAltitudeColor(p2.alt);
-                const line = L.polyline([[p1.lat, p1.lon], [p2.lat, p2.lon]], {
-                    color: color,
-                    weight: 2,
-                    opacity: opacity
-                }).addTo(radarMap);
-                trailLines[icao].push(line);
+            for (let i = 1; i < trail.length; i++) {
+                const p = trail[i];
+                const color = getAltitudeColor(p.alt);
+
+                if (color !== runColor) {
+                    // Flush the current color run as one polyline
+                    if (runPoints.length >= 2) {
+                        const opacity = Math.max(0.2, 1 - ((now - runEndTime) / 1000 / 120));
+                        trailLines[icao].push(
+                            L.polyline(runPoints, { color: runColor, weight: 2, opacity }).addTo(radarMap)
+                        );
+                    }
+                    // Start a new run, sharing the junction point for visual continuity
+                    runColor = color;
+                    runPoints = [[trail[i-1].lat, trail[i-1].lon], [p.lat, p.lon]];
+                } else {
+                    runPoints.push([p.lat, p.lon]);
+                }
+                runEndTime = p.time;
+            }
+
+            // Flush the final run
+            if (runPoints.length >= 2) {
+                const opacity = Math.max(0.2, 1 - ((now - runEndTime) / 1000 / 120));
+                trailLines[icao].push(
+                    L.polyline(runPoints, { color: runColor, weight: 2, opacity }).addTo(radarMap)
+                );
             }
         }
 

templates/index.html

@@ -2696,7 +2696,7 @@
                         <div class="wxsat-strip-divider"></div>
                         <div class="wxsat-strip-group">
                             <label class="wxsat-schedule-toggle" title="Auto-capture passes">
-                                <input type="checkbox" id="wxsatAutoSchedule" onchange="WeatherSat.toggleScheduler()">
+                                <input type="checkbox" id="wxsatAutoSchedule" onchange="WeatherSat.toggleScheduler(this)">
                                 <span class="wxsat-toggle-label">AUTO</span>
                             </label>
                         </div>
@@ -4036,6 +4036,11 @@
                 if (typeof SpaceWeather !== 'undefined' && SpaceWeather.destroy) SpaceWeather.destroy();
             }
 
+            // Suspend Weather Satellite background timers/streams when leaving the mode
+            if (mode !== 'weathersat') {
+                if (typeof WeatherSat !== 'undefined' && WeatherSat.suspend) WeatherSat.suspend();
+            }
+
             // Show/hide Device Intelligence for modes that use it (not for satellite/aircraft/tscm)
             const reconBtn = document.getElementById('reconBtn');
             const intelBtn = document.querySelector('[onclick="exportDeviceDB()"]');

templates/partials/modes/weather-satellite.html

@@ -226,7 +226,7 @@
         </p>
         <div class="form-group">
             <label style="display: flex; align-items: center; gap: 6px;">
-                <input type="checkbox" id="wxsatSidebarAutoSchedule" onchange="WeatherSat.toggleScheduler()" style="width: auto;">
+                <input type="checkbox" id="wxsatSidebarAutoSchedule" onchange="WeatherSat.toggleScheduler(this)" style="width: auto;">
                 Enable Auto-Capture
             </label>
         </div>

utils/weather_sat_predict.py

@@ -105,7 +105,7 @@ def predict_passes(
                 ).total_seconds()
                 duration_minutes = round(duration_seconds / 60, 1)
 
-                # Calculate max elevation and trajectory
+                # Calculate max elevation (always) and trajectory points (only if requested)
                 max_el = 0.0
                 max_el_az = 0.0
                 trajectory: list[dict[str, float]] = []
@@ -141,14 +141,14 @@ def predict_passes(
                 _, set_az, _ = set_topo.altaz()
 
                 pass_data: dict[str, Any] = {
-                    'id': f"{sat_key}_{rise_time.utc_datetime().strftime('%Y%m%d%H%M')}",
+                    'id': f"{sat_key}_{rise_time.utc_datetime().strftime('%Y%m%d%H%M%S')}",
                     'satellite': sat_key,
                     'name': sat_info['name'],
                     'frequency': sat_info['frequency'],
                     'mode': sat_info['mode'],
                     'startTime': rise_time.utc_datetime().strftime('%Y-%m-%d %H:%M UTC'),
-                    'startTimeISO': rise_time.utc_datetime().isoformat(),
-                    'endTimeISO': set_time.utc_datetime().isoformat(),
+                    'startTimeISO': rise_time.utc_datetime().isoformat() + 'Z',
+                    'endTimeISO': set_time.utc_datetime().isoformat() + 'Z',
                     'maxEl': round(max_el, 1),
                     'maxElAz': round(max_el_az, 1),
                     'riseAz': round(rise_az.degrees, 1),