feat: Claude Web UI POC with streaming and tool visualization

Initial implementation of a web-based Claude Code interface with:

Backend (Node.js + Express + WebSocket):
- Claude CLI spawning with JSON stream mode
- Session management with resume support (--continue flag)
- Session history API endpoint
- Real-time WebSocket communication
- --include-partial-messages for live streaming

Frontend (React + Vite + Tailwind):
- Modern dark theme UI (Discord/Slack style)
- Live text streaming with content_block_delta handling
- Markdown rendering with react-markdown + remark-gfm
- Syntax highlighting with react-syntax-highlighter (One Dark)
- Collapsible high-tech tool cards with:
  - Tool-specific icons and colors
  - Compact summaries (Read, Glob, Bash, Edit, etc.)
  - Expandable JSON details
- Session history loading on resume
- Project directory selection
- Resume session toggle

Docker:
- Multi-container setup (backend + nginx frontend)
- Isolated Claude config directory
- Host network mode for backend

Built collaboratively by Neko (VPS Claude) and Web-UI Claude,
with Web-UI Claude implementing most frontend features while
running inside the interface itself (meta-programming!).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/public/claude.svg

@@ -0,0 +1,10 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
+  <defs>
+    <linearGradient id="grad" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" style="stop-color:#f97316;stop-opacity:1" />
+      <stop offset="100%" style="stop-color:#ea580c;stop-opacity:1" />
+    </linearGradient>
+  </defs>
+  <rect width="100" height="100" rx="20" fill="url(#grad)"/>
+  <text x="50" y="68" font-family="Arial, sans-serif" font-size="50" font-weight="bold" fill="white" text-anchor="middle">C</text>
+</svg>