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- Remove 9 outdated specification docs (v0.2.0 API design)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/developer/development-setup.md

@@ -0,0 +1,71 @@
+# Development Setup
+
+Local development without Docker.
+
+---
+
+## Prerequisites
+
+- Python 3.10+
+- pip
+- virtualenv
+
+---
+
+## Setup Steps
+
+### 1. Clone Repository
+
+```bash
+git clone https://github.com/Xe138/AI-Trader.git
+cd AI-Trader
+```
+
+### 2. Create Virtual Environment
+
+```bash
+python3 -m venv venv
+source venv/bin/activate  # Linux/Mac
+# venv\Scripts\activate  # Windows
+```
+
+### 3. Install Dependencies
+
+```bash
+pip install -r requirements.txt
+```
+
+### 4. Configure Environment
+
+```bash
+cp .env.example .env
+# Edit .env with your API keys
+```
+
+### 5. Start MCP Services
+
+```bash
+cd agent_tools
+python start_mcp_services.py &
+cd ..
+```
+
+### 6. Start API Server
+
+```bash
+python -m uvicorn api.main:app --reload --port 8080
+```
+
+---
+
+## Running Tests
+
+```bash
+pytest tests/ -v
+```
+
+---
+
+## Project Structure
+
+See [CLAUDE.md](../../CLAUDE.md) for complete project structure.