style(ext/vault): add patina palette tokens

Mirrors popup/styles.css token block so the two surfaces share a
consistent color vocabulary.

extension/src/vault/vault.css

@@ -1,22 +1,35 @@
 /* Relicario vault — terminal dark theme (tab layout) */
 
 :root {
-  /* Brand */
-  --accent:        #d2ab43;
-  --accent-soft:   rgba(210, 171, 67, 0.18);
-  --accent-strong: #aa812a;
+  /* Patina gold (Phase 2B) */
+  --gold-base:   #a88a4a;
+  --gold-mid:    #cdb47a;
+  --gold-shadow: #5a3f12;
+  --gold-text:   #c9a868;
+  --gold-soft:   rgba(184, 149, 86, 0.14);
+  --gold-ring:   rgba(184, 149, 86, 0.18);
+  --gold-stroke: #b89556;
+  --gold-hi-end: #dac8a0;
+
+  /* Brand alias (kept for backwards compatibility) */
+  --accent:        var(--gold-base);
+  --accent-soft:   var(--gold-soft);
+  --accent-strong: var(--gold-shadow);
 
   /* Surfaces */
-  --bg-page:       #0d1117;
-  --bg-pane:       #161b22;
-  --bg-elevated:   #21262d;
-  --bg-input:      #161b22;
-  --border-subtle: #30363d;
+  --bg-page:       #0a0e14;
+  --bg-pane:       #11161e;
+  --bg-elevated:   #1c2330;
+  --bg-card:       rgba(22, 27, 34, 0.55);
+  --bg-input:      #0a0e14;
+  --border-soft:   rgba(255, 255, 255, 0.05);
+  --border-mid:    #262d36;
+  --border-subtle: var(--border-mid);
 
   /* Text */
   --text:          #c9d1d9;
   --text-muted:    #8b949e;
-  --text-dim:      #484f58;
+  --text-dim:      #6b7888;
 
   /* Status */
   --danger:        #ab2b20;
@@ -24,7 +37,7 @@
   --success:       #6cb37a;
 
   /* Focus */
-  --focus-ring:    0 0 0 2px rgba(210, 171, 67, 0.35);
+  --focus-ring:    0 0 0 2px var(--gold-ring);
 }
 
 * {
@@ -34,7 +47,7 @@
 }
 
 body {
-  background: #0d1117;
+  background: var(--bg-page);
   color: #c9d1d9;
   font-family: 'JetBrains Mono', 'Cascadia Code', 'Fira Code', 'SF Mono', Menlo, monospace;
   font-size: 13px;
@@ -62,7 +75,7 @@ body {
 .brand {
   font-size: 16px;
   font-weight: 700;
-  color: #d2ab43;
+  color: var(--gold-text);
   letter-spacing: 1px;
 }