Remove sensor-waterfall panels and default recon mode to off

- Remove waterfall UI panels from pager and 433MHz sections
- Remove associated JS functions (toggle, render, data tracking)
- Remove waterfall CSS styles
- Change recon mode to default to 'off' instead of 'on'

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

static/css/index.css

@@ -1872,21 +1872,6 @@ header h1 .tagline {
     background: var(--accent-cyan);
 }
 
-/* Waterfall canvases (inside collapsible panels) */
-#waterfallCanvas,
-#sensorWaterfallCanvas {
-    width: 100%;
-    height: 30px;
-    background: var(--bg-primary);
-    border: none;
-    display: block;
-}
-
-#waterfallCanvas.active,
-#sensorWaterfallCanvas.active {
-    border-color: var(--accent-cyan);
-}
-
 .status-controls {
     display: flex;
     gap: 8px;
@@ -2011,63 +1996,6 @@ header h1 .tagline {
     font-weight: bold;
 }
 
-/* Removed - now using sensor-waterfall-panel structure for waterfalls */
-
-/* Waterfall Panel (used for both pager and 433MHz modes) */
-.sensor-waterfall-panel {
-    margin: 0 15px 10px 15px;
-    background: var(--bg-secondary);
-    border: 1px solid var(--border-color);
-    border-radius: 4px;
-    overflow: hidden;
-}
-
-.sensor-waterfall-header {
-    display: flex;
-    align-items: center;
-    gap: 8px;
-    padding: 8px 12px;
-    background: var(--bg-tertiary);
-    border-bottom: 1px solid var(--border-color);
-    font-size: 11px;
-    font-weight: 600;
-    color: var(--text-secondary);
-    text-transform: uppercase;
-    letter-spacing: 0.5px;
-    user-select: none;
-}
-
-.sensor-waterfall-header:hover {
-    background: var(--bg-hover);
-}
-
-.sensor-waterfall-content {
-    background: #000;
-    transition: max-height 0.3s ease, padding 0.3s ease;
-    max-height: 50px;
-    overflow: hidden;
-}
-
-.sensor-waterfall-panel.collapsed .sensor-waterfall-content {
-    max-height: 0;
-    padding: 0;
-}
-
-.sensor-waterfall-panel.collapsed .sensor-waterfall-header {
-    border-bottom: none;
-}
-
-/* Removed duplicate - consolidated above */
-
-.waterfall-scale {
-    display: flex;
-    justify-content: space-between;
-    padding: 4px 8px;
-    font-size: 9px;
-    color: var(--text-dim);
-    background: rgba(0, 0, 0, 0.5);
-}
-
 .spectrum-legend {
     display: flex;
     align-items: center;
@@ -2113,10 +2041,6 @@ header h1 .tagline {
     color: var(--bg-primary);
 }
 
-#waterfallCanvas {
-    cursor: crosshair;
-}
-
 /* Channel Recommendation */
 .channel-recommendation {
     background: var(--bg-card);