docs: restructure documentation for improved clarity and navigation

Reorganize documentation into user-focused, developer-focused, and deployment-focused sections.

**New structure:**
- Root: README.md (streamlined), QUICK_START.md, API_REFERENCE.md
- docs/user-guide/: configuration, API usage, integrations, troubleshooting
- docs/developer/: contributing, development setup, testing, architecture
- docs/deployment/: Docker deployment, production checklist, monitoring
- docs/reference/: environment variables, MCP tools, data formats

**Changes:**
- Streamline README.md from 831 to 469 lines
- Create QUICK_START.md for 5-minute onboarding
- Create API_REFERENCE.md as single source of truth for API
- Remove 9 outdated specification docs (v0.2.0 API design)
- Remove DOCKER_API.md (content consolidated into new structure)
- Remove docs/plans/ directory with old design documents
- Update CLAUDE.md with documentation structure guide
- Remove orchestration-specific references

**Benefits:**
- Clear entry points for different audiences
- No content duplication
- Better discoverability through logical hierarchy
- All content reflects current v0.3.0 API

docs/reference/mcp-tools.md

@@ -0,0 +1,39 @@
+# MCP Tools Reference
+
+Model Context Protocol tools available to AI agents.
+
+---
+
+## Available Tools
+
+### Math Tool (Port 8000)
+Mathematical calculations and analysis.
+
+### Search Tool (Port 8001)
+Market intelligence via Jina AI search.
+- News articles
+- Analyst reports
+- Financial data
+
+### Trade Tool (Port 8002)
+Buy/sell execution.
+- Place orders
+- Check balances
+- View positions
+
+### Price Tool (Port 8003)
+Historical and current price data.
+- OHLCV data
+- Multiple symbols
+- Date filtering
+
+---
+
+## Usage
+
+AI agents access tools automatically through MCP protocol.
+Tools are localhost-only and not exposed to external network.
+
+---
+
+See `agent_tools/` directory for implementations.