feat: add dock with open-indicator dots

src/components/Dock/Dock.css

@@ -0,0 +1,52 @@
+.dock-container {
+  position: fixed;
+  bottom: 8px;
+  left: 50%;
+  transform: translateX(-50%);
+  z-index: 500;
+}
+
+.dock {
+  display: flex;
+  align-items: flex-end;
+  gap: 6px;
+  background: rgba(30, 30, 40, 0.52);
+  backdrop-filter: var(--glass-blur);
+  -webkit-backdrop-filter: var(--glass-blur);
+  border: 1px solid var(--glass-border);
+  border-radius: 18px;
+  padding: 8px 12px;
+  box-shadow: 0 4px 28px rgba(0,0,0,0.4);
+}
+
+.dock-item {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 3px;
+  cursor: pointer;
+  position: relative;
+}
+
+.dock-item:hover .dock-icon {
+  transform: scale(1.18) translateY(-6px);
+}
+
+.dock-icon {
+  width: 48px;
+  height: 48px;
+  border-radius: 12px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 24px;
+  transition: transform 0.15s ease;
+  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
+}
+
+.dock-dot {
+  width: 4px;
+  height: 4px;
+  border-radius: 50%;
+  background: rgba(255,255,255,0.7);
+}

src/components/Dock/Dock.tsx

@@ -0,0 +1,36 @@
+import './Dock.css';
+import { useOS } from '../../context/WindowContext';
+import { APPS } from '../../config/apps';
+
+export default function Dock() {
+  const { state, openWindow, focusWindow } = useOS();
+
+  function handleClick(id: string) {
+    const win = state.windows[id];
+    if (!win.isOpen) {
+      openWindow(id);
+    } else {
+      // focusWindow also sets isMinimized: false, so this handles both minimized and normal cases
+      focusWindow(id);
+    }
+  }
+
+  return (
+    <div className="dock-container">
+      <div className="dock">
+        {APPS.map(app => {
+          const win = state.windows[app.id];
+          const isOpen = win.isOpen;
+          return (
+            <div key={app.id} className="dock-item" onClick={() => handleClick(app.id)}>
+              <div className="dock-icon" style={{ background: app.iconGradient }}>
+                <span>{app.emoji}</span>
+              </div>
+              {isOpen && <div className="dock-dot" />}
+            </div>
+          );
+        })}
+      </div>
+    </div>
+  );
+}