Fix multiple UI bugs and improve error handling

Issues fixed:
- #113: Display RTL-SDR serial numbers in device selector
- #112: Kill all processes now stops Bluetooth scans
- #111: BLE device list no longer overflows container bounds
- #109: WiFi scanner panels maintain minimum width (no more "imploding")
- #108: Radar device hover no longer causes violent shaking
- #106: "Use GPS" button now uses gpsd for USB GPS devices
- #105: Meter trend text no longer overlaps adjacent columns
- #104: dump1090 errors now provide specific troubleshooting guidance

Changes:
- app.py: Add Bluetooth cleanup to /killall endpoint
- routes/adsb.py: Parse dump1090 stderr for specific error messages
- templates/index.html: Show SDR serial numbers in device dropdown
- static/css/index.css: Fix WiFi/BT panel layouts with proper min-width
- static/css/components/signal-cards.css: Fix meter grid overflow
- static/css/components/proximity-viz.css: Fix radar hover transform
- static/css/settings.css: Add GPS detection spinner
- static/js/components/proximity-radar.js: Add invisible hit areas
- static/js/core/settings-manager.js: Use gpsd before browser geolocation

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

static/css/components/proximity-viz.css

@@ -14,10 +14,18 @@
 
 .radar-device {
     transition: transform 0.2s ease;
+    transform-origin: center center;
+    cursor: pointer;
 }
 
 .radar-device:hover {
-    transform: scale(1.3);
+    transform: scale(1.2);
+}
+
+/* Invisible larger hit area to prevent hover flicker */
+.radar-device-hitarea {
+    fill: transparent;
+    pointer-events: all;
 }
 
 .radar-dot-pulse circle:first-child {

static/css/components/signal-cards.css

@@ -1020,6 +1020,8 @@
     display: flex;
     flex-direction: column;
     gap: 4px;
+    min-width: 0; /* Allow column to shrink in grid */
+    overflow: hidden;
 }
 
 .meter-aggregated-label {
@@ -1034,6 +1036,9 @@
     font-size: 16px;
     font-weight: 600;
     color: var(--text-primary);
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
 }
 
 /* Consumption column */
@@ -1068,6 +1073,8 @@
     min-height: 28px;
     display: flex;
     align-items: center;
+    max-width: 100%;
+    overflow: hidden;
 }
 
 .meter-sparkline-placeholder {
@@ -1082,6 +1089,9 @@
     font-size: 14px;
     font-weight: 500;
     color: var(--accent-cyan, #4a9eff);
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
 }
 
 /* Update animation */

static/css/index.css

@@ -1590,6 +1590,11 @@ header h1 .tagline {
     box-shadow: 0 0 0 2px var(--accent-cyan-dim);
 }
 
+/* Ensure device select is wide enough for device name + serial */
+#deviceSelect {
+    min-width: 280px;
+}
+
 .checkbox-group {
     display: flex;
     flex-wrap: wrap;
@@ -3383,7 +3388,7 @@ header h1 .tagline {
 /* WiFi Main Content - 3 columns */
 .wifi-main-content {
     display: grid;
-    grid-template-columns: 1fr minmax(240px, 280px) minmax(240px, 280px);
+    grid-template-columns: minmax(300px, 1fr) minmax(240px, 280px) minmax(240px, 280px);
     gap: 10px;
     flex: 1;
     min-height: 0;
@@ -3398,6 +3403,7 @@ header h1 .tagline {
     border: 1px solid var(--border-color);
     border-radius: 4px;
     overflow: hidden;
+    min-width: 0; /* Prevent content from forcing panel wider */
 }
 
 .wifi-networks-header {
@@ -3565,6 +3571,8 @@ header h1 .tagline {
     border: 1px solid var(--border-color);
     border-radius: 4px;
     padding: 12px;
+    min-width: 0; /* Prevent content from forcing panel wider */
+    overflow: hidden;
 }
 
 .wifi-radar-panel h5 {
@@ -3803,7 +3811,7 @@ header h1 .tagline {
 /* WiFi Responsive */
 @media (max-width: 1400px) {
     .wifi-main-content {
-        grid-template-columns: 1fr 240px 240px;
+        grid-template-columns: minmax(280px, 1fr) 240px 240px;
     }
 }
 
@@ -4104,10 +4112,37 @@ header h1 .tagline {
 
 .bt-device-list {
     border-left-color: var(--accent-purple) !important;
+    display: flex;
+    flex-direction: column;
+    min-width: 280px;
+    max-width: 320px;
+    max-height: 100%;
+    background: var(--bg-primary);
+    border: 1px solid var(--border-color);
+    border-radius: 4px;
+    overflow: hidden;
+}
+
+.bt-device-list .wifi-device-list-content {
+    flex: 1;
+    overflow-y: auto;
+    min-height: 0;
+}
+
+.bt-device-list .wifi-device-list-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 10px 12px;
+    border-bottom: 1px solid var(--border-color);
+    flex-shrink: 0;
 }
 
 .bt-device-list .wifi-device-list-header h5 {
     color: var(--accent-purple);
+    margin: 0;
+    font-size: 13px;
+    font-weight: 600;
 }
 
 /* Bluetooth Device Filters */
@@ -4117,6 +4152,7 @@ header h1 .tagline {
     padding: 8px 12px;
     border-bottom: 1px solid var(--border-color);
     flex-wrap: wrap;
+    flex-shrink: 0;
 }
 
 .bt-filter-btn {

static/css/settings.css

@@ -326,6 +326,23 @@
     cursor: not-allowed;
 }
 
+/* GPS Detection Spinner */
+.detecting-spinner {
+    display: inline-block;
+    width: 12px;
+    height: 12px;
+    border: 2px solid currentColor;
+    border-top-color: transparent;
+    border-radius: 50%;
+    animation: detecting-spin 0.8s linear infinite;
+    vertical-align: middle;
+    margin-right: 6px;
+}
+
+@keyframes detecting-spin {
+    to { transform: rotate(360deg); }
+}
+
 /* About Section */
 .about-info {
     font-size: 13px;