refactor: Flatten directory structure

Move project files from uzdb/ subdirectory to root directory for cleaner project structure.

Changes:
- Move frontend/ to root
- Move internal/ to root
- Move build/ to root
- Move all config files (go.mod, wails.json, etc.) to root
- Remove redundant uzdb/ subdirectory nesting

Project structure is now:
├── frontend/        # React application
├── internal/        # Go backend
├── build/           # Wails build assets
├── doc/             # Design documentation
├── main.go          # Entry point
└── ...

🤖 Generated with Qoder

frontend/src/components/Layout/ToolBar.css

@@ -0,0 +1,124 @@
+/**
+ * ToolBar Component Styles
+ */
+
+.toolbar {
+  display: flex;
+  align-items: center;
+  height: var(--toolbar-height);
+  padding: 0 var(--space-4);
+  background-color: var(--bg-primary);
+  border-bottom: 1px solid var(--border);
+  gap: var(--space-4);
+  flex-shrink: 0;
+}
+
+.toolbar-buttons {
+  display: flex;
+  gap: var(--space-1);
+}
+
+.toolbar-button {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+  padding: var(--space-2) var(--space-3);
+  font-size: var(--text-sm);
+  font-family: var(--font-sans);
+  color: var(--text-primary);
+  background: transparent;
+  border: 1px solid transparent;
+  border-radius: var(--radius-md);
+  cursor: pointer;
+  transition: all var(--transition-fast) var(--ease-in-out);
+  white-space: nowrap;
+}
+
+.toolbar-button:hover:not(.disabled) {
+  background-color: var(--bg-tertiary);
+  border-color: var(--border);
+}
+
+.toolbar-button.disabled {
+  color: var(--text-muted);
+  cursor: not-allowed;
+}
+
+.button-icon {
+  font-size: var(--text-base);
+}
+
+.button-label {
+  font-weight: 500;
+}
+
+.toolbar-content {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+}
+
+.toolbar-spacer {
+  flex: 1;
+}
+
+/* Connection indicator */
+.toolbar-connection {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+  padding: var(--space-2) var(--space-3);
+  background-color: var(--bg-secondary);
+  border: 1px solid var(--border);
+  border-radius: var(--radius-md);
+  cursor: pointer;
+  transition: all var(--transition-fast) var(--ease-in-out);
+}
+
+.toolbar-connection:hover {
+  background-color: var(--bg-tertiary);
+  border-color: var(--text-secondary);
+}
+
+.connection-status-dot {
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  background-color: var(--text-muted);
+}
+
+.connection-status-dot.connected {
+  background-color: var(--success);
+  box-shadow: 0 0 4px var(--success);
+}
+
+.connection-name {
+  font-size: var(--text-sm);
+  font-weight: 500;
+  color: var(--text-primary);
+}
+
+.dropdown-arrow {
+  font-size: var(--text-xs);
+  color: var(--text-muted);
+}
+
+/* Responsive adjustments */
+@media (max-width: 768px) {
+  .toolbar {
+    padding: 0 var(--space-2);
+    gap: var(--space-2);
+  }
+
+  .toolbar-button {
+    padding: var(--space-2);
+  }
+
+  .button-label {
+    display: none;
+  }
+
+  .connection-name {
+    display: none;
+  }
+}