Fix WiFi table columns and channel chart overflow

Table fixes:
- Add BSSID column header to match data columns
- Remove vendor column from table rows (6 columns total)
- Update placeholder colspan to 6

Layout fixes:
- Use minmax() for right columns to allow shrinking
- Add overflow handling to layout container
- Add min-width: 0 to analysis panel for proper grid behavior
- Add overflow-x: auto to channel chart container

Channel chart fixes:
- Reduce bar width from 20px to 14px
- Reduce bar spacing from 4px to 2px
- Reduce padding for more compact display
- Use viewBox for responsive SVG scaling

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

static/css/index.css

@@ -3154,6 +3154,8 @@ header h1 .tagline {
     border: 1px solid var(--border-color);
     height: calc(100vh - 200px);
     min-height: 400px;
+    box-sizing: border-box;
+    overflow: hidden;
 }
 
 /* WiFi Status Bar */
@@ -3201,11 +3203,11 @@ header h1 .tagline {
 /* WiFi Main Content - 3 columns */
 .wifi-main-content {
     display: grid;
-    grid-template-columns: 1fr 280px 280px;
+    grid-template-columns: 1fr minmax(240px, 280px) minmax(240px, 280px);
     gap: 10px;
     flex: 1;
     min-height: 0;
-    overflow: hidden;
+    overflow: auto;
 }
 
 /* WiFi Networks Panel (LEFT) */
@@ -3435,6 +3437,8 @@ header h1 .tagline {
     display: flex;
     flex-direction: column;
     gap: 10px;
+    min-width: 0;
+    overflow: hidden;
 }
 
 .wifi-channel-section,
@@ -3488,6 +3492,8 @@ header h1 .tagline {
 
 .wifi-channel-chart {
     min-height: 120px;
+    overflow-x: auto;
+    overflow-y: hidden;
 }
 
 .wifi-security-stats {