hotfix(dc/tool-c): Fix compute formula validation and binning NaN serialization

Critical fixes:
1. Compute column: Add Chinese comma support in formula validation
   - Problem: Formula with Chinese comma failed validation
   - Fix: Add Chinese comma character to allowed_chars regex
   - Example: Support formulas like 'col1（kg）+ col2，col3'

2. Binning operation: Fix NaN serialization error
   - Problem: 'Out of range float values are not JSON compliant: nan'
   - Fix: Enhanced NaN/inf handling in binning endpoint
   - Added np.inf/-np.inf replacement before JSON serialization
   - Added manual JSON serialization with NaN->null conversion

3. Enhanced all operation endpoints for consistency
   - Updated conditional, dropna endpoints with same NaN/inf handling
   - Ensures all operations return JSON-compliant data

Modified files:
- extraction_service/operations/compute.py: Add Chinese comma to regex
- extraction_service/main.py: Enhanced NaN handling in binning/conditional/dropna

Status: Hotfix complete, ready for testing

docs/03-业务模块/DC-数据清洗整理/06-开发记录/2025-12-06_工具C_Day2开发完成总结.md

@@ -602,3 +602,4 @@ import { logger } from '../../../../common/logging/index.js';
 
 
 
+