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>

backend/Dockerfile

@@ -0,0 +1,36 @@
+FROM node:20-slim
+
+# Create app directory
+WORKDIR /app
+
+# Create node user home structure for claude
+RUN mkdir -p /home/node/.local/bin && \
+    mkdir -p /home/node/.local/share/claude && \
+    mkdir -p /home/node/.claude && \
+    mkdir -p /home/node/.config/claude && \
+    chown -R node:node /home/node
+
+# Create symlink for claude binary
+RUN ln -s /home/node/.local/share/claude/versions/2.0.67 /home/node/.local/bin/claude
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm install --production
+
+# Copy app source
+COPY . .
+
+# Set ownership
+RUN chown -R node:node /app
+
+# Switch to node user
+USER node
+
+# Set PATH to include claude
+ENV PATH="/home/node/.local/bin:${PATH}"
+
+EXPOSE 3001
+
+CMD ["node", "server.js"]