PWA对话界面重构 + 记忆库桥接

- 纯对话界面：消息气泡、深灰输入框
- 桥接服务接入 DeepSeek API
- 记忆库文件纳入 mao1 仓库（含沈晏身份/对话规则）
- 移除 ModelSelector、光晕效果等无关元素

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

PWA/src/index.css

@@ -9,25 +9,12 @@
 html, body, #root {
   height: 100%;
   background: #000;
-  color: #e5e5e5;
   font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", sans-serif;
   -webkit-font-smoothing: antialiased;
   overflow: hidden;
   user-select: none;
 }
 
-.glow-area {
-  position: relative;
-}
-.glow-area::before {
-  content: '';
-  position: absolute;
-  inset: 0;
-  background: radial-gradient(ellipse 65% 80% at 50% 50%, rgba(255,255,255,0.035) 0%, transparent 70%);
-  pointer-events: none;
-  z-index: 0;
-}
-
 .no-scrollbar::-webkit-scrollbar {
   display: none;
 }