feat: standardize UI theme, fix dark mode consistency, and implement editorial tags

memento-note/app/globals.css

@@ -25,10 +25,10 @@
   --color-background-dark: #202020;
 
   /* Design tokens from architectural-grid 10 */
-  --color-ink: #1C1C1C;
-  --color-paper: #F2F0E9;
-  --color-muted-ink: rgba(28, 28, 28, 0.6);
-  --color-concrete: #8D8D8D;
+  --color-ink: var(--ink);
+  --color-paper: var(--paper);
+  --color-muted-ink: var(--muted-ink);
+  --color-concrete: var(--concrete);
   --color-blueprint: #75B2D6;
   --color-ochre: #D4A373;
   --color-sage: #A3B18A;
@@ -183,6 +183,7 @@ html:not(.dark) .memento-active-nav {
   --ink: var(--foreground);
   --paper: var(--background);
   --muted-ink: var(--muted-foreground);
+  --concrete: #8D8D8D;
   --ai-accent: #ACB995;
 }
 
@@ -424,6 +425,8 @@ html.dark {
   --sidebar-accent-foreground: #1C1C1C;
   --sidebar-border: rgba(28, 28, 28, 0.1);
   --sidebar-ring: rgba(28, 28, 28, 0.35);
+  --thumb-lightness-1: 94%;
+  --thumb-lightness-2: 87%;
 }
 
 [data-theme='light'].dark {
@@ -487,6 +490,9 @@ html.dark {
   --sidebar-accent-foreground: #ffffff;
   --sidebar-border: #3d3d3d;
   --sidebar-ring: #a8a29e;
+  --thumb-lightness-1: 15%;
+  --thumb-lightness-2: 10%;
+  --concrete: #A0A0A0;
 }
 
 [data-theme='midnight'] {