feat: Add customizable TP size percentages and fix settings save

**New Features:**
- Added TAKE_PROFIT_1_SIZE_PERCENT (default: 50%)
- Added TAKE_PROFIT_2_SIZE_PERCENT (default: 50%)
- Users can now control WHAT % to close at each TP level
- Risk calculator now shows actual TP sizes dynamically

**Bug Fixes:**
- Fixed settings save failure by mounting .env file to container
- Added .env volume mount in docker-compose.yml
- Fixed permission issues (.env must be chmod 666)

**UI Changes:**
- Split TP controls into Price % and Size %
- TP1 Price: When to exit first partial
- TP1 Size: What % of position to close (1-100%)
- TP2 Price: When to exit second partial
- TP2 Size: What % of remaining to close (1-100%)
- Risk calculator displays dynamic percentages

**Example:**
- TP1 at +1% price, close 60% of position
- TP2 at +2% price, close 40% of remaining (24% of original)
- Total exit: 84% of position at TP levels

docker-compose.yml

@@ -49,6 +49,9 @@ services:
       DRY_RUN: ${DRY_RUN:-false}
     
     volumes:
+      # Mount .env file for settings persistence
+      - ./.env:/app/.env
+      
       # Mount logs directory
       - ./logs:/app/logs