dashboard: fix gauge charts (install gauge.js, render after polls), force dark theme with white text and red/green accents, add icons

static/dashboard.css

@@ -8,12 +8,43 @@
 :root {
   --xau-font-sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
   --xau-font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Consolas, Menlo, monospace;
+  --xau-gold: #f5b301;
+}
+
+/* Forced dark theme (owner decision 2026-08-16): dark background, pure
+ * white text (no gray), vivid red/green for data accents. Loaded after
+ * Bootstrap so these overrides win. */
+[data-bs-theme="dark"] {
+  --bs-body-bg: #0a0e14;
+  --bs-secondary-bg: #111823;
+  --bs-tertiary-bg: #0e141d;
+  --bs-body-color: #ffffff;
+  --bs-emphasis-color: #ffffff;
+  --bs-heading-color: #ffffff;
+  --bs-secondary-color: rgba(255, 255, 255, 0.92);
+  --bs-tertiary-color: rgba(255, 255, 255, 0.8);
+  --bs-border-color: rgba(255, 255, 255, 0.14);
+  --bs-card-bg: #0e141d;
+  --bs-card-border-color: rgba(255, 255, 255, 0.12);
+  --bs-modal-bg: #0e141d;
+  --bs-success: #22c55e;
+  --bs-success-rgb: 34, 197, 94;
+  --bs-success-text-emphasis: #4ade80;
+  --bs-success-bg-subtle: rgba(34, 197, 94, 0.16);
+  --bs-success-border-subtle: rgba(34, 197, 94, 0.45);
+  --bs-danger: #ef4444;
+  --bs-danger-rgb: 239, 68, 68;
+  --bs-danger-text-emphasis: #f87171;
+  --bs-danger-bg-subtle: rgba(239, 68, 68, 0.16);
+  --bs-danger-border-subtle: rgba(239, 68, 68, 0.45);
 }
 
 html, body {
   font-family: var(--xau-font-sans);
   letter-spacing: -0.005em;
   -webkit-font-smoothing: antialiased;
+  background-color: var(--bs-body-bg);
+  color: var(--bs-body-color);
 }
 
 .num, .xau-price, .xau-symbol {
@@ -25,12 +56,12 @@ html, body {
   font-size: 0.95rem;
   font-weight: 700;
   letter-spacing: 0.08em;
-  color: var(--bs-primary);
+  color: var(--xau-gold);
 }
 
 .xau-price {
   line-height: 1;
-  color: var(--bs-primary-text-emphasis);
+  color: #ffffff;
 }
 
 .live-dot {
@@ -100,6 +131,14 @@ html, body {
   overflow: hidden;
 }
 
+/* Chart.js gauge canvas host (see gauge.js) — thin bar in the row */
+.scorebar .gauge-container {
+  position: relative;
+  flex: 1;
+  min-width: 60px;
+  height: 22px;
+}
+
 .scorebar .track::after {
   content: "";
   position: absolute;