feat(desktop): add Electron desktop pet for Claude CLI

- Electron + React + TypeScript 桌面宠物外壳
- xterm.js + node-pty 直接对接 Claude CLI 进程
- 宠物 orb（80x80）可拖拽，点击展开终端面板
- CRT 复古终端主题（扫描线、文字发光）
- 全局快捷键 Cmd+Shift+C 显隐
- 窗口位置自动保存
- 中华田园犬吉祥物 icon（AI 生成）
- Makefile 新增 `make app` 打包命令

desktop/src/index.css

@@ -0,0 +1,127 @@
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+
+body {
+  background: transparent;
+  overflow: hidden;
+  font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
+}
+
+#root {
+  width: 100vw;
+  height: 100vh;
+}
+
+/* CRT Terminal Effects */
+.crt-container {
+  position: relative;
+}
+
+.crt-container::before {
+  content: '';
+  position: absolute;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background: repeating-linear-gradient(
+    0deg,
+    rgba(0, 0, 0, 0.08),
+    rgba(0, 0, 0, 0.08) 1px,
+    transparent 1px,
+    transparent 2px
+  );
+  pointer-events: none;
+  z-index: 10;
+}
+
+.crt-container::after {
+  content: '';
+  position: absolute;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background: radial-gradient(
+    ellipse at center,
+    transparent 50%,
+    rgba(0, 0, 0, 0.3) 100%
+  );
+  pointer-events: none;
+  z-index: 11;
+}
+
+/* Terminal text glow */
+.xterm-viewport {
+  background-color: transparent !important;
+}
+
+.xterm-screen {
+  text-shadow: 0 0 2px rgba(74, 222, 128, 0.3), 0 0 4px rgba(74, 222, 128, 0.1) !important;
+}
+
+/* Flicker animation */
+@keyframes flicker {
+  0% { opacity: 0.98; }
+  5% { opacity: 0.95; }
+  10% { opacity: 0.98; }
+  15% { opacity: 0.96; }
+  20% { opacity: 0.99; }
+  50% { opacity: 0.98; }
+  52% { opacity: 0.93; }
+  54% { opacity: 0.98; }
+  100% { opacity: 0.98; }
+}
+
+.crt-flicker {
+  animation: flicker 4s infinite;
+}
+
+/* Scanline sweep */
+@keyframes scanline {
+  0% { transform: translateY(-100%); }
+  100% { transform: translateY(100vh); }
+}
+
+.crt-scanline {
+  position: absolute;
+  top: 0;
+  left: 0;
+  right: 0;
+  height: 4px;
+  background: linear-gradient(
+    to bottom,
+    transparent,
+    rgba(74, 222, 128, 0.08),
+    transparent
+  );
+  animation: scanline 8s linear infinite;
+  pointer-events: none;
+  z-index: 12;
+}
+
+/* Pet Orb Animations */
+@keyframes orbBreathe {
+  0%, 100% { transform: scale(1); }
+  50% { transform: scale(1.06); }
+}
+
+@keyframes orbThink {
+  0%, 100% { transform: scale(1) rotate(0deg); }
+  25% { transform: scale(1.1) rotate(-5deg); }
+  75% { transform: scale(1.1) rotate(5deg); }
+}
+
+@keyframes orbType {
+  0%, 100% { transform: translateY(0); }
+  25% { transform: translateY(-2px); }
+  75% { transform: translateY(1px); }
+}
+
+@keyframes orbGlow {
+  0%, 100% { box-shadow: 0 4px 16px rgba(22, 163, 74, 0.4), inset 0 2px 4px rgba(255,255,255,0.2); }
+  50% { box-shadow: 0 4px 24px rgba(74, 222, 128, 0.6), inset 0 2px 4px rgba(255,255,255,0.3); }
+}