fix: resolve two-window hang and sweep UI/theming updates

Fix app becoming unresponsive when two browser windows are open: the
root cause was HTTP/1.1 connection pool exhaustion (6-connection limit
per origin). VoiceAlerts was opening 3 SSE streams per window by
default, so two windows produced 8 connections and permanently starved
all regular HTTP requests.

- voice-alerts.js: default all streams to false (opt-in) to stay within
  the browser connection limit; existing user preferences in localStorage
  are preserved
- routes/alerts.py: replace direct AlertManager.stream_events() with
  sse_stream_fanout so both windows receive every alert instead of
  competing for the same queue
- routes/bluetooth_v2.py: same fanout fix via subscribe_fanout_queue,
  preserving named SSE events (device_update, scan_started, etc.)

Also includes accumulated UI/theming changes: accent-cyan CSS variable
sweep across mode CSS/JS files, standalone dashboard pages, template
updates, satellite TLE data refresh, and tile provider default rename.

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

static/css/modes/bt_locate.css

@@ -284,7 +284,7 @@
 #btLocateMap {
     position: absolute;
     inset: 0;
-    background: #1a1a2e;
+    background: var(--bg-primary, #07090e);
 }
 
 .btl-map-overlay-controls {
@@ -442,8 +442,8 @@
     text-transform: uppercase;
     letter-spacing: 0.5px;
     color: var(--accent-cyan, #00d4ff);
-    background: rgba(0, 212, 255, 0.1);
-    border: 1px solid rgba(0, 212, 255, 0.3);
+    background: rgba(var(--accent-cyan-rgb), 0.1);
+    border: 1px solid rgba(var(--accent-cyan-rgb), 0.3);
     border-radius: 4px;
     cursor: pointer;
     transition: all 0.2s;
@@ -452,7 +452,7 @@
 }
 
 .btl-detect-irk-btn:hover {
-    background: rgba(0, 212, 255, 0.2);
+    background: rgba(var(--accent-cyan-rgb), 0.2);
     border-color: var(--accent-cyan, #00d4ff);
 }
 

static/css/modes/meteor.css

@@ -471,3 +471,26 @@
         height: 40px;
     }
 }
+
+html[data-ui-tier="enhanced"] .meteor-visuals-container {
+    --ms-border: rgba(46, 125, 138, 0.22);
+    --ms-surface: linear-gradient(180deg, rgba(2, 6, 6, 0.97) 0%, rgba(1, 3, 3, 0.98) 100%);
+    --ms-accent: #2e7d8a;
+    --ms-accent-dim: rgba(46, 125, 138, 0.12);
+    background: radial-gradient(circle at 14% -18%, rgba(46, 125, 138, 0.10) 0%, rgba(46, 125, 138, 0) 38%),
+        radial-gradient(circle at 86% -26%, rgba(46, 125, 138, 0.07) 0%, rgba(46, 125, 138, 0) 36%),
+        #000202;
+}
+
+html[data-ui-tier="enhanced"] .ms-headline,
+html[data-ui-tier="enhanced"] .ms-events-panel {
+    background: rgba(2, 6, 6, 0.9);
+}
+
+html[data-ui-tier="enhanced"] .ms-events-table th {
+    background: rgba(2, 6, 6, 0.95);
+}
+
+html[data-ui-tier="enhanced"] .ms-events-table tr:hover td {
+    background: rgba(46, 125, 138, 0.04);
+}

static/css/modes/morse.css

@@ -199,3 +199,17 @@
         align-items: stretch;
     }
 }
+
+html[data-ui-tier="enhanced"] .morse-raw-panel {
+    border-color: rgba(46, 125, 138, 0.18);
+    background: rgba(1, 4, 4, 0.9);
+}
+
+html[data-ui-tier="enhanced"] .morse-raw-text {
+    color: rgba(70, 180, 200, 0.90);
+}
+
+html[data-ui-tier="enhanced"] .morse-metrics-panel span {
+    border-color: rgba(46, 125, 138, 0.18);
+    background: rgba(1, 4, 4, 0.88);
+}

static/css/modes/radiosonde.css

@@ -160,14 +160,14 @@
     flex-direction: column;
     align-items: center;
     padding: 4px 10px;
-    background: rgba(0, 229, 255, 0.05);
-    border: 1px solid rgba(0, 229, 255, 0.15);
+    background: rgba(var(--accent-cyan-rgb), 0.05);
+    border: 1px solid rgba(var(--accent-cyan-rgb), 0.15);
     border-radius: 4px;
     min-width: 55px;
 }
 .radiosonde-strip .strip-stat:hover {
-    background: rgba(0, 229, 255, 0.1);
-    border-color: rgba(0, 229, 255, 0.3);
+    background: rgba(var(--accent-cyan-rgb), 0.1);
+    border-color: rgba(var(--accent-cyan-rgb), 0.3);
 }
 .radiosonde-strip .strip-value {
     font-family: var(--font-mono);

static/css/modes/sstv-general.css

@@ -342,7 +342,7 @@
 .sstv-general-image-card:hover {
     border-color: var(--accent-cyan);
     transform: translateY(-2px);
-    box-shadow: 0 4px 12px rgba(0, 212, 255, 0.2);
+    box-shadow: 0 4px 12px rgba(var(--accent-cyan-rgb), 0.2);
 }
 
 .sstv-general-image-card-inner {

static/css/modes/sstv.css

@@ -401,7 +401,7 @@
 .sstv-image-card:hover {
     border-color: var(--accent-cyan);
     transform: translateY(-2px);
-    box-shadow: 0 4px 12px rgba(0, 212, 255, 0.2);
+    box-shadow: 0 4px 12px rgba(var(--accent-cyan-rgb), 0.2);
 }
 
 .sstv-image-card-inner {
@@ -688,7 +688,7 @@
     font-weight: 700;
     color: var(--accent-cyan);
     letter-spacing: 2px;
-    text-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
+    text-shadow: 0 0 20px rgba(var(--accent-cyan-rgb), 0.3);
 }
 
 .sstv-countdown-value.imminent {

static/css/modes/subghz.css

@@ -300,7 +300,7 @@
 }
 
 .subghz-btn.active {
-    background: rgba(0, 212, 255, 0.1);
+    background: rgba(var(--accent-cyan-rgb), 0.1);
     border-color: var(--accent-cyan, var(--accent-cyan));
     color: var(--accent-cyan, var(--accent-cyan));
 }
@@ -384,9 +384,9 @@
 }
 
 .subghz-capture-card.selected {
-    border-color: rgba(0, 212, 255, 0.85);
-    box-shadow: 0 0 0 1px rgba(0, 212, 255, 0.3);
-    background: rgba(0, 212, 255, 0.06);
+    border-color: rgba(var(--accent-cyan-rgb), 0.85);
+    box-shadow: 0 0 0 1px rgba(var(--accent-cyan-rgb), 0.3);
+    background: rgba(var(--accent-cyan-rgb), 0.06);
 }
 
 .subghz-capture-header {
@@ -455,9 +455,9 @@
 }
 
 .subghz-capture-tag.auto {
-    border-color: rgba(0, 212, 255, 0.55);
+    border-color: rgba(var(--accent-cyan-rgb), 0.55);
     color: var(--accent-cyan);
-    background: rgba(0, 212, 255, 0.12);
+    background: rgba(var(--accent-cyan-rgb), 0.12);
 }
 
 .subghz-capture-tag.hint {
@@ -536,13 +536,13 @@
 }
 
 .subghz-capture-actions button.select-btn {
-    border-color: rgba(0, 212, 255, 0.5);
+    border-color: rgba(var(--accent-cyan-rgb), 0.5);
     color: var(--accent-cyan);
 }
 
 .subghz-capture-actions button.select-btn.selected {
-    border-color: rgba(0, 212, 255, 0.9);
-    background: rgba(0, 212, 255, 0.18);
+    border-color: rgba(var(--accent-cyan-rgb), 0.9);
+    background: rgba(var(--accent-cyan-rgb), 0.18);
     color: #7beeff;
 }
 
@@ -781,14 +781,14 @@
     height: 26px;
     border: 1px solid var(--border-color, #2a3040);
     border-radius: 4px;
-    background: linear-gradient(90deg, rgba(0, 212, 255, 0.07), rgba(255, 170, 0, 0.07));
+    background: linear-gradient(90deg, rgba(var(--accent-cyan-rgb), 0.07), rgba(255, 170, 0, 0.07));
     margin-bottom: 8px;
     overflow: hidden;
 }
 
 .subghz-tx-burst-timeline.dragging {
-    border-color: rgba(0, 212, 255, 0.65);
-    box-shadow: 0 0 0 1px rgba(0, 212, 255, 0.25) inset;
+    border-color: rgba(var(--accent-cyan-rgb), 0.65);
+    box-shadow: 0 0 0 1px rgba(var(--accent-cyan-rgb), 0.25) inset;
 }
 
 .subghz-tx-burst-selection {
@@ -796,8 +796,8 @@
     top: 3px;
     bottom: 3px;
     border-radius: 3px;
-    border: 1px solid rgba(0, 212, 255, 0.95);
-    background: rgba(0, 212, 255, 0.22);
+    border: 1px solid rgba(var(--accent-cyan-rgb), 0.95);
+    background: rgba(var(--accent-cyan-rgb), 0.22);
     pointer-events: none;
     display: none;
     z-index: 2;
@@ -823,8 +823,8 @@
 }
 
 .subghz-tx-burst-marker:hover {
-    background: rgba(0, 212, 255, 0.85);
-    border-color: rgba(0, 212, 255, 1);
+    background: rgba(var(--accent-cyan-rgb), 0.85);
+    border-color: rgba(var(--accent-cyan-rgb), 1);
 }
 
 .subghz-tx-burst-list {
@@ -861,7 +861,7 @@
 
 .subghz-tx-burst-item button {
     padding: 2px 8px;
-    border: 1px solid rgba(0, 212, 255, 0.5);
+    border: 1px solid rgba(var(--accent-cyan-rgb), 0.5);
     border-radius: 3px;
     background: transparent;
     color: var(--accent-cyan);
@@ -871,7 +871,7 @@
 }
 
 .subghz-tx-burst-item button:hover {
-    background: rgba(0, 212, 255, 0.12);
+    background: rgba(var(--accent-cyan-rgb), 0.12);
 }
 
 .subghz-tx-modal-actions {
@@ -901,13 +901,13 @@
 }
 
 .subghz-tx-trim-btn {
-    background: rgba(0, 212, 255, 0.14);
+    background: rgba(var(--accent-cyan-rgb), 0.14);
     color: var(--accent-cyan);
-    border-color: rgba(0, 212, 255, 0.55) !important;
+    border-color: rgba(var(--accent-cyan-rgb), 0.55) !important;
 }
 
 .subghz-tx-trim-btn:hover {
-    background: rgba(0, 212, 255, 0.26);
+    background: rgba(var(--accent-cyan-rgb), 0.26);
 }
 
 .subghz-tx-cancel-btn {
@@ -1043,7 +1043,7 @@
 }
 
 .subghz-action-btn.decode:hover {
-    background: rgba(0, 212, 255, 0.12);
+    background: rgba(var(--accent-cyan-rgb), 0.12);
     border-color: var(--accent-cyan, var(--accent-cyan));
     color: var(--accent-cyan, var(--accent-cyan));
 }
@@ -1275,7 +1275,7 @@
 
 .subghz-phase-step.active {
     color: var(--accent-cyan, var(--accent-cyan));
-    text-shadow: 0 0 6px rgba(0, 212, 255, 0.3);
+    text-shadow: 0 0 6px rgba(var(--accent-cyan-rgb), 0.3);
 }
 
 .subghz-phase-step.completed {
@@ -1328,9 +1328,9 @@
 }
 
 .subghz-burst-indicator.recent {
-    border-color: rgba(0, 212, 255, 0.45);
+    border-color: rgba(var(--accent-cyan-rgb), 0.45);
     color: var(--accent-cyan);
-    background: rgba(0, 212, 255, 0.1);
+    background: rgba(var(--accent-cyan-rgb), 0.1);
 }
 
 .subghz-burst-indicator.recent .subghz-burst-dot {
@@ -1445,8 +1445,8 @@
     transform: translateY(0);
 }
 
-.subghz-hub-card--cyan { border-color: rgba(0, 212, 255, 0.2); }
-.subghz-hub-card--cyan:hover { border-color: var(--accent-cyan, var(--accent-cyan)); background: rgba(0, 212, 255, 0.05); }
+.subghz-hub-card--cyan { border-color: rgba(var(--accent-cyan-rgb), 0.2); }
+.subghz-hub-card--cyan:hover { border-color: var(--accent-cyan, var(--accent-cyan)); background: rgba(var(--accent-cyan-rgb), 0.05); }
 .subghz-hub-card--cyan .subghz-hub-icon { color: var(--accent-cyan, var(--accent-cyan)); }
 
 .subghz-hub-card--green { border-color: rgba(0, 255, 136, 0.2); }
@@ -1736,8 +1736,8 @@
 
 .subghz-rx-burst-pill.recent {
     color: var(--accent-cyan);
-    border-color: rgba(0, 212, 255, 0.65);
-    background: rgba(0, 212, 255, 0.12);
+    border-color: rgba(var(--accent-cyan-rgb), 0.65);
+    background: rgba(var(--accent-cyan-rgb), 0.12);
 }
 
 .subghz-rx-level-label {

static/css/modes/system.css

@@ -17,7 +17,7 @@
     text-transform: uppercase;
     letter-spacing: 0.12em;
     color: var(--accent-cyan, #00d4ff);
-    border-bottom: 1px solid rgba(0, 212, 255, 0.2);
+    border-bottom: 1px solid rgba(var(--accent-cyan-rgb), 0.2);
     padding-bottom: 6px;
     margin-top: 8px;
 }
@@ -221,7 +221,7 @@
     fill: none;
     stroke: var(--accent-cyan, #00d4ff);
     stroke-width: 1.5;
-    filter: drop-shadow(0 0 2px rgba(0, 212, 255, 0.4));
+    filter: drop-shadow(0 0 2px rgba(var(--accent-cyan-rgb), 0.4));
 }
 
 .sys-sparkline-area {

static/css/modes/waterfall.css

@@ -1180,3 +1180,139 @@
     font-family: var(--font-mono, monospace);
     font-size: 9px;
 }
+
+/* ---- Enhanced tier: replace blue palette with signals teal ---- */
+
+html[data-ui-tier="enhanced"] .wf-container {
+    --wf-border: rgba(46, 125, 138, 0.22);
+    --wf-surface: linear-gradient(180deg, rgba(2, 6, 6, 0.97) 0%, rgba(1, 3, 3, 0.98) 100%);
+    background: radial-gradient(circle at 14% -18%, rgba(46, 125, 138, 0.08) 0%, rgba(46, 125, 138, 0) 38%),
+        radial-gradient(circle at 86% -26%, rgba(46, 125, 138, 0.05) 0%, rgba(46, 125, 138, 0) 36%),
+        #000202;
+}
+
+html[data-ui-tier="enhanced"] .wf-headline {
+    background: rgba(2, 6, 6, 0.86);
+}
+
+html[data-ui-tier="enhanced"] .wf-headline-tag {
+    color: rgba(70, 185, 200, 0.90);
+}
+
+html[data-ui-tier="enhanced"] .wf-rx-vfo {
+    border-color: rgba(46, 125, 138, 0.25);
+    background: linear-gradient(180deg, rgba(3, 8, 8, 0.92) 0%, rgba(1, 4, 4, 0.95) 100%);
+}
+
+html[data-ui-tier="enhanced"] .wf-rx-vfo-status {
+    color: rgba(65, 175, 192, 0.88);
+}
+
+html[data-ui-tier="enhanced"] .wf-rx-vfo-readout {
+    color: rgba(80, 190, 205, 0.92);
+}
+
+html[data-ui-tier="enhanced"] #wfRxFreqReadout {
+    text-shadow: 0 0 16px rgba(46, 125, 138, 0.25);
+}
+
+html[data-ui-tier="enhanced"] .wf-rx-modebank {
+    border-color: rgba(46, 125, 138, 0.22);
+    background: rgba(1, 4, 4, 0.86);
+}
+
+html[data-ui-tier="enhanced"] .wf-mode-btn {
+    border-color: rgba(46, 125, 138, 0.24);
+    background: linear-gradient(180deg, rgba(4, 8, 8, 0.95) 0%, rgba(2, 5, 5, 0.95) 100%);
+    color: rgba(65, 175, 192, 0.90);
+}
+
+html[data-ui-tier="enhanced"] .wf-mode-btn:hover {
+    border-color: rgba(46, 125, 138, 0.48);
+}
+
+html[data-ui-tier="enhanced"] .wf-mode-btn.is-active,
+html[data-ui-tier="enhanced"] .wf-mode-btn.active {
+    border-color: rgba(46, 125, 138, 0.62);
+    background: linear-gradient(180deg, rgba(6, 16, 18, 0.92) 0%, rgba(4, 12, 14, 0.95) 100%);
+    color: rgba(100, 210, 222, 0.96);
+    box-shadow: 0 0 14px rgba(46, 125, 138, 0.22);
+}
+
+html[data-ui-tier="enhanced"] .wf-rx-levels,
+html[data-ui-tier="enhanced"] .wf-rx-meter-wrap,
+html[data-ui-tier="enhanced"] .wf-rx-actions {
+    border-color: rgba(46, 125, 138, 0.20);
+    background: rgba(1, 4, 4, 0.85);
+}
+
+html[data-ui-tier="enhanced"] .wf-monitor-select {
+    border-color: rgba(46, 125, 138, 0.25);
+    background: rgba(1, 3, 3, 0.8);
+}
+
+html[data-ui-tier="enhanced"] .wf-rx-smeter-fill {
+    box-shadow: 0 0 10px rgba(46, 125, 138, 0.22);
+}
+
+html[data-ui-tier="enhanced"] .wf-monitor-btn-secondary {
+    border-color: rgba(46, 125, 138, 0.45);
+    background: linear-gradient(180deg, rgba(4, 12, 14, 0.95) 0%, rgba(2, 8, 10, 0.95) 100%);
+    color: rgba(80, 190, 205, 0.90);
+}
+
+html[data-ui-tier="enhanced"] .wf-freq-bar {
+    background: rgba(2, 6, 6, 0.78);
+}
+
+html[data-ui-tier="enhanced"] .wf-spectrum-canvas-wrap {
+    background: radial-gradient(circle at 50% -120%, rgba(46, 125, 138, 0.06) 0%, rgba(46, 125, 138, 0) 65%);
+}
+
+html[data-ui-tier="enhanced"] .wf-band-strip {
+    background: linear-gradient(180deg, rgba(2, 6, 6, 0.96) 0%, rgba(1, 3, 3, 0.98) 100%);
+}
+
+html[data-ui-tier="enhanced"] .wf-band-block {
+    border-color: rgba(46, 125, 138, 0.42);
+    color: rgba(80, 190, 205, 0.92);
+}
+
+html[data-ui-tier="enhanced"] .wf-band-edge {
+    color: rgba(65, 175, 192, 0.88);
+}
+
+html[data-ui-tier="enhanced"] .wf-band-marker::before {
+    background: rgba(46, 125, 138, 0.58);
+    box-shadow: 0 0 5px rgba(46, 125, 138, 0.30);
+}
+
+html[data-ui-tier="enhanced"] .wf-band-marker-label {
+    border-color: rgba(46, 125, 138, 0.48);
+    background: rgba(2, 5, 5, 0.95);
+    color: rgba(80, 190, 205, 0.90);
+}
+
+html[data-ui-tier="enhanced"] .wf-tune-line {
+    background: rgba(46, 125, 138, 0.72);
+}
+
+html[data-ui-tier="enhanced"] .wf-freq-axis {
+    background: rgba(2, 6, 6, 0.86);
+}
+
+html[data-ui-tier="enhanced"] .wf-side .section.wf-side-hero {
+    background: linear-gradient(180deg, rgba(3, 8, 8, 0.95) 0%, rgba(1, 4, 4, 0.97) 100%);
+    border-color: rgba(46, 125, 138, 0.30);
+    box-shadow: 0 8px 24px rgba(0, 8, 10, 0.30), inset 0 0 0 1px rgba(255, 255, 255, 0.03);
+}
+
+html[data-ui-tier="enhanced"] .wf-side-chip {
+    color: rgba(65, 175, 192, 0.88);
+    border-color: rgba(46, 125, 138, 0.32);
+    background: rgba(6, 16, 18, 0.30);
+}
+
+html[data-ui-tier="enhanced"] .wf-side-stat {
+    border-color: rgba(46, 125, 138, 0.20);
+}

static/css/modes/weather-satellite.css

@@ -308,7 +308,7 @@
     opacity: 1;
 }
 
-.wxsat-timeline-pass.apt { background: rgba(0, 212, 255, 0.6); }
+.wxsat-timeline-pass.apt { background: rgba(var(--accent-cyan-rgb), 0.6); }
 .wxsat-timeline-pass.lrpt { background: rgba(0, 255, 136, 0.6); }
 .wxsat-timeline-pass.scheduled { border: 1px solid var(--accent-yellow); }
 
@@ -585,7 +585,7 @@
 }
 
 .wxsat-pass-mode.apt {
-    background: rgba(0, 212, 255, 0.15);
+    background: rgba(var(--accent-cyan-rgb), 0.15);
     color: var(--accent-cyan);
 }
 
@@ -626,7 +626,7 @@
 }
 
 .wxsat-pass-quality.good {
-    background: rgba(0, 212, 255, 0.15);
+    background: rgba(var(--accent-cyan-rgb), 0.15);
     color: var(--accent-cyan);
 }
 
@@ -759,16 +759,16 @@
 
 .wxsat-map-tooltip {
     background: rgba(5, 15, 32, 0.92);
-    border: 1px solid rgba(102, 229, 255, 0.65);
+    border: 1px solid rgba(var(--accent-cyan-rgb), 0.65);
     border-radius: 4px;
-    color: #8fe8ff;
+    color: var(--accent-cyan);
     box-shadow: 0 0 12px rgba(0, 210, 255, 0.24);
     font-size: 10px;
     letter-spacing: 0.25px;
 }
 
 .wxsat-map-tooltip.leaflet-tooltip-top:before {
-    border-top-color: rgba(102, 229, 255, 0.65);
+    border-top-color: rgba(var(--accent-cyan-rgb), 0.65);
 }
 
 /* ===== Image Gallery Panel ===== */
@@ -1221,8 +1221,8 @@
 
 .wxsat-phase-step.completed {
     color: var(--accent-cyan, #00d4ff);
-    border-color: rgba(0, 212, 255, 0.3);
-    background: rgba(0, 212, 255, 0.05);
+    border-color: rgba(var(--accent-cyan-rgb), 0.3);
+    background: rgba(var(--accent-cyan-rgb), 0.05);
     opacity: 0.7;
 }
 
@@ -1267,7 +1267,7 @@
 .wxsat-console-filter.active {
     border-color: var(--accent-cyan, #00d4ff);
     color: var(--accent-cyan, #00d4ff);
-    background: rgba(0, 212, 255, 0.08);
+    background: rgba(var(--accent-cyan-rgb), 0.08);
 }
 
 .wxsat-console-actions {