feat: simplify Docker config file selection with convention over configuration

Implement automatic detection of custom_config.json for simpler Docker usage.
No environment variables or command-line arguments needed for most users.

Changes:
- entrypoint.sh: Add smart config detection (custom_config.json > CLI arg > default_config.json)
- docker-compose.yml: Add configs volume mount for editing without rebuilds
- docs/DOCKER.md: Update documentation with simplified workflow
- .gitignore: Add custom_config.json to prevent accidental commits

Usage:
  cp configs/default_config.json configs/custom_config.json
  nano configs/custom_config.json
  docker-compose up  # Automatically uses custom_config.json

Simplifies user experience by following convention over configuration principle.

.gitignore

@@ -57,6 +57,7 @@ delete.py
 refresh_data.sh
 
 # Config files (optional - uncomment if needed)
+configs/custom_config.json
 configs/day_config.json
 configs/hour_config.json
 configs/test_config.json

docker-compose.yml

@@ -7,6 +7,7 @@ services:
     volumes:
       - ./data:/app/data
       - ./logs:/app/logs
+      - ./configs:/app/configs
     environment:
       # AI Model API Configuration
       - OPENAI_API_BASE=${OPENAI_API_BASE}

docs/DOCKER.md

@@ -53,10 +53,30 @@ AGENT_MAX_STEP=30
 
 ### Custom Trading Configuration
 
-Pass a custom config file:
+**Simple Method (Recommended):**
+
+Create a `configs/custom_config.json` file - it will be automatically used:
 
 ```bash
-docker-compose run ai-trader configs/my_config.json
+# Copy default config as starting point
+cp configs/default_config.json configs/custom_config.json
+
+# Edit your custom config
+nano configs/custom_config.json
+
+# Run normally - custom_config.json is automatically detected!
+docker-compose up
+```
+
+**Priority order:**
+1. `configs/custom_config.json` (if exists) - **Highest priority**
+2. Command-line argument: `docker-compose run ai-trader configs/other.json`
+3. `configs/default_config.json` (fallback)
+
+**Advanced: Use a different config file name:**
+
+```bash
+docker-compose run ai-trader configs/my_special_config.json
 ```
 
 ## Usage Examples
@@ -92,10 +112,11 @@ docker-compose up
 
 ### Volume Mounts
 
-Docker Compose mounts two volumes:
+Docker Compose mounts three volumes:
 
 - `./data:/app/data` - Price data and trading records
 - `./logs:/app/logs` - MCP service logs
+- `./configs:/app/configs` - Configuration files (allows editing configs without rebuilding)
 
 Data persists across container restarts. To reset:
 
@@ -227,13 +248,45 @@ Services exposed on host:
 
 ### Test Different Configurations
 
-```bash
-# Create test config
-cp configs/default_config.json configs/test_config.json
-# Edit test_config.json
+**Method 1: Use the standard custom_config.json**
 
-# Run with test config
-docker-compose run ai-trader configs/test_config.json
+```bash
+# Create and edit your config
+cp configs/default_config.json configs/custom_config.json
+nano configs/custom_config.json
+
+# Run - automatically uses custom_config.json
+docker-compose up
+```
+
+**Method 2: Test multiple configs with different names**
+
+```bash
+# Create multiple test configs
+cp configs/default_config.json configs/conservative.json
+cp configs/default_config.json configs/aggressive.json
+
+# Edit each config...
+
+# Test conservative strategy
+docker-compose run ai-trader configs/conservative.json
+
+# Test aggressive strategy
+docker-compose run ai-trader configs/aggressive.json
+```
+
+**Method 3: Temporarily switch configs**
+
+```bash
+# Temporarily rename your custom config
+mv configs/custom_config.json configs/custom_config.json.backup
+cp configs/test_strategy.json configs/custom_config.json
+
+# Run with test strategy
+docker-compose up
+
+# Restore original
+mv configs/custom_config.json.backup configs/custom_config.json
 ```
 
 ## Production Deployment

entrypoint.sh

@@ -57,7 +57,19 @@ sleep 3
 
 # Step 4: Run trading agent with config file
 echo "🤖 Starting trading agent..."
-CONFIG_FILE="${1:-configs/default_config.json}"
+
+# Smart config selection: custom_config.json takes precedence if it exists
+if [ -f "configs/custom_config.json" ]; then
+    CONFIG_FILE="configs/custom_config.json"
+    echo "✅ Using custom configuration: configs/custom_config.json"
+elif [ -n "$1" ]; then
+    CONFIG_FILE="$1"
+    echo "✅ Using specified configuration: $CONFIG_FILE"
+else
+    CONFIG_FILE="configs/default_config.json"
+    echo "✅ Using default configuration: configs/default_config.json"
+fi
+
 python main.py "$CONFIG_FILE"
 
 # Cleanup on exit