style: reduce grid gaps to 6px

frontend/src/pages/AlphaPage.css

@@ -92,7 +92,7 @@
 .alpha-filter-fields {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));
-  gap: 16px;
+  gap: 6px;
 }
 .alpha-filter-fields > label {
   margin: 0;

frontend/src/pages/home.css

@@ -44,7 +44,7 @@
 .home-metrics {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));
-  gap: 16px;
+  gap: 6px;
   margin-bottom: 20px;
 }
 .home-metric.semi-card,
@@ -142,7 +142,7 @@
 .home-panel-error {
   display: grid;
   justify-items: start;
-  gap: 16px;
+  gap: 6px;
   min-height: 180px;
 }
 .home-calendar-summary {

frontend/src/pages/mcp-keys.css

@@ -62,7 +62,7 @@
 .mcp-key-permissions {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
-  gap: 16px;
+  gap: 6px;
 }
 .mcp-key-permissions label {
   display: flex;