fix: corrections UI — indicateur voute, couleurs, statut IA, spinner éditeur

1. Suppression du badge vault-context-pill doublon en mobile
2. Couleurs dynamiques indicateur header:
   - Bleu pour 'All' (.vault-ctx-all)
   - Mauve/violet pour les vaults (.vault-ctx-vault)
   - Jaune/ambre pour les répertoires (.vault-ctx-dir)
3. Statut IA: vérifie la présence du toolbar AI dans le DOM
   au lieu d'appeler /api/ai/status (qui ne fonctionnait pas)
4. Indicateur de traitement AI dans l'éditeur (spinner + badge
   'AI...' dans le header de l'editor modal) au lieu du flash
   blanc sur le badge sync

frontend/style.css

@@ -171,24 +171,48 @@ a:hover {
   align-items: center;
   gap: 6px;
   padding: 6px 12px;
-  background: color-mix(in srgb, var(--accent) 12%, transparent);
-  border: 1px solid color-mix(in srgb, var(--accent) 25%, var(--border));
+  border: 1px solid var(--border);
   border-radius: 8px;
   font-family: "JetBrains Mono", monospace;
   font-size: 0.75rem;
   font-weight: 600;
-  color: var(--accent);
   cursor: default;
   transition: all 200ms ease;
+  /* Default: neutral (overridden by classes below) */
+  background: var(--bg-tertiary);
+  color: var(--text-muted);
 }
 .vault-context-indicator:hover {
-  background: color-mix(in srgb, var(--accent) 18%, transparent);
-  border-color: var(--accent);
+  filter: brightness(1.15);
 }
 .vault-context-indicator i {
-  color: var(--accent);
+  opacity: 0.8;
 }
 
+/* All vaults — blue */
+.vault-ctx-all {
+  background: color-mix(in srgb, #3b82f6 14%, transparent) !important;
+  border-color: color-mix(in srgb, #3b82f6 30%, var(--border)) !important;
+  color: #60a5fa !important;
+}
+.vault-ctx-all i { color: #60a5fa !important; }
+
+/* Specific vault — mauve/violet */
+.vault-ctx-vault {
+  background: color-mix(in srgb, #a855f7 14%, transparent) !important;
+  border-color: color-mix(in srgb, #a855f7 30%, var(--border)) !important;
+  color: #c084fc !important;
+}
+.vault-ctx-vault i { color: #c084fc !important; }
+
+/* Directory — amber/yellow */
+.vault-ctx-dir {
+  background: color-mix(in srgb, #f59e0b 14%, transparent) !important;
+  border-color: color-mix(in srgb, #f59e0b 30%, var(--border)) !important;
+  color: #fbbf24 !important;
+}
+.vault-ctx-dir i { color: #fbbf24 !important; }
+
 .hamburger-btn {
   display: none;
   background: none;
@@ -2150,6 +2174,41 @@ select {
   top: 0;
   z-index: 10;
 }
+
+/* AI processing indicator — shown inside editor header during AI calls */
+.ai-processing-indicator {
+  display: none;
+  align-items: center;
+  gap: 6px;
+  padding: 3px 10px;
+  border-radius: 12px;
+  font-size: 0.72rem;
+  font-weight: 500;
+  color: #ffffff;
+  background: rgba(59, 130, 246, 0.3);
+  border: 1px solid rgba(96, 165, 250, 0.4);
+  animation: ai-indicator-pulse 1s ease-in-out infinite;
+  margin-left: 12px;
+}
+
+.ai-spinner {
+  width: 10px;
+  height: 10px;
+  border: 2px solid rgba(255,255,255,0.3);
+  border-top-color: #ffffff;
+  border-radius: 50%;
+  animation: ai-spinner-spin 0.6s linear infinite;
+}
+
+@keyframes ai-spinner-spin {
+  to { transform: rotate(360deg); }
+}
+
+@keyframes ai-indicator-pulse {
+  0%, 100% { opacity: 1; }
+  50% { opacity: 0.6; }
+}
+
 .editor-title {
   font-family: "JetBrains Mono", monospace;
   font-size: 0.9rem;
@@ -6825,22 +6884,12 @@ body.popup-mode .content-area {
     display: none !important;
   }
 
-  /* Vault context indicator */
+  /* Vault context indicator — hidden (now in header) */
   .vault-context-bar {
-    display: flex;
-    align-items: center;
-    padding: 6px 14px;
-    background: var(--bg-primary);
-    border-bottom: 1px solid var(--border);
+    display: none !important;
   }
   .vault-context-pill {
-    font-size: 0.72rem;
-    font-weight: 600;
-    color: var(--accent);
-    background: color-mix(in srgb, var(--accent) 10%, transparent);
-    padding: 3px 10px;
-    border-radius: 12px;
-    white-space: nowrap;
+    display: none;
   }
 
   .mt-btn {