feat: implement three-mode UI system (Easy / Pro / Chat)

Add switchable UI modes with conditional rendering:
- Easy mode: goal-based interface with 7 guided workflows
- Pro mode: current technical interface preserved with Quick Start Goals
- Chat mode: AIUI placeholder for future integration

New components: ModeSwitcher, EasyHome, GoalDetail wizard, Chat placeholder
New stores: uiMode (mode persistence), goals (progress tracking)
New data: goal definitions catalog, helpTree goals section
Modified: Dashboard (reactive nav), Home (mode dispatcher), Settings (mode picker),
Router (goal/chat routes), Spotlight (goal search integration)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

neode-ui/src/style.css

@@ -67,6 +67,95 @@
     overflow-y: visible;
   }
 
+  /* Mode switcher - sidebar toggle */
+  .mode-switcher {
+    display: flex;
+    gap: 2px;
+    padding: 3px;
+    border-radius: 0.5rem;
+    background: rgba(255, 255, 255, 0.06);
+    border: 1px solid rgba(255, 255, 255, 0.08);
+  }
+
+  .mode-switcher-btn {
+    flex: 1;
+    padding: 0.375rem 0.5rem;
+    border-radius: 0.375rem;
+    font-size: 0.75rem;
+    font-weight: 500;
+    color: rgba(255, 255, 255, 0.45);
+    transition: all 0.25s ease;
+    cursor: pointer;
+    text-align: center;
+    border: none;
+    background: transparent;
+  }
+
+  .mode-switcher-btn:hover {
+    color: rgba(255, 255, 255, 0.75);
+  }
+
+  .mode-switcher-btn-active {
+    background: rgba(255, 255, 255, 0.15);
+    color: rgba(255, 255, 255, 0.95);
+    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
+  }
+
+  /* Goal cards */
+  .goal-card {
+    cursor: pointer;
+    transition: all 0.3s ease;
+  }
+
+  .goal-card:hover {
+    transform: translateY(-2px);
+  }
+
+  .goal-status-badge {
+    display: inline-flex;
+    align-items: center;
+    gap: 0.375rem;
+    padding: 0.25rem 0.625rem;
+    border-radius: 9999px;
+    font-size: 0.75rem;
+    font-weight: 500;
+  }
+
+  .goal-status-badge-not-started {
+    background: rgba(255, 255, 255, 0.08);
+    color: rgba(255, 255, 255, 0.5);
+  }
+
+  .goal-status-badge-in-progress {
+    background: rgba(251, 146, 60, 0.15);
+    color: #fb923c;
+  }
+
+  .goal-status-badge-completed {
+    background: rgba(74, 222, 128, 0.15);
+    color: #4ade80;
+  }
+
+  /* Goal wizard steps */
+  .goal-step {
+    padding: 1rem 1.25rem;
+    border-left: 3px solid rgba(255, 255, 255, 0.1);
+    transition: all 0.3s ease;
+  }
+
+  .goal-step-active {
+    border-left-color: #fb923c;
+    background: rgba(251, 146, 60, 0.05);
+  }
+
+  .goal-step-completed {
+    border-left-color: #4ade80;
+  }
+
+  .goal-step-pending {
+    opacity: 0.5;
+  }
+
   .glass-button {
     position: relative;
     display: inline-flex;