fix: navbar single-line, chart sizing, text visibility

- Removed hamburger menu — all stats inline on one navbar row
- Disconnect button at top-right (ms-auto)
- Added data-bs-theme=dark for proper BS5 dark mode text inheritance
- Restored explicit width/height on chart SVGs (required by NVD3)
- Changed text-muted → text-white-50 for field labels on dark bg
- Added flex-nowrap to navbar container
- Overrode --bs-body-bg to maintain original dark shade

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

rcon.css

@@ -5,6 +5,8 @@
   --rcon-text: #cfd2da;
   --rcon-accent: #1ca8dd;
   --rcon-card-bg: #434857;
+  /* Override BS5 dark theme body background */
+  --bs-body-bg: #252830;
 }
 
 body {
@@ -79,7 +81,7 @@ a:hover { color: #fff; text-decoration: none; }
   box-shadow: 0 0 0 0.2rem rgba(28, 168, 221, 0.25);
 }
 
-/* Card dark theme */
+/* Cards — override BS dark-theme bg to our darker shade */
 .card {
   background-color: var(--rcon-card-bg);
   border-color: rgba(255, 255, 255, 0.1);
@@ -104,7 +106,7 @@ a:hover { color: #fff; text-decoration: none; }
   border-color: rgba(255, 255, 255, 0.15);
 }
 
-/* Navbar text color override for dark theme */
+/* Navbar text color override */
 .navbar-dark .navbar-text {
   color: rgba(255, 255, 255, 0.85);
 }
@@ -116,9 +118,9 @@ a:hover { color: #fff; text-decoration: none; }
   border-bottom: 1px solid rgba(255, 255, 255, 0.15);
 }
 
-/* Chart panels */
+/* Chart SVGs */
 #chart-performance,
 #chart-network,
 #chart-players {
-  min-height: 200px;
+  display: block;
 }