[Enhancement] Runtime confidence threshold tuning

[zeemscript]

Summary

Enable dynamic adjustment of confidence thresholds for retrieval and response generation at runtime without code deployment, with per-topic and per-source customization.

Current State

Confidence thresholds are hardcoded. Adjusting thresholds requires code changes and redeployment, preventing quick optimization.

Acceptance Criteria

• Expose confidence threshold configuration via admin interface
• Support different thresholds per Islamic topic category
• Allow source-specific confidence requirements
• Enable A/B testing of different threshold values
• Track impact of threshold changes on response quality
• Provide recommendations based on performance data
• Support gradual threshold adjustments
• Implement safeguards against extreme values
• Log threshold changes in audit trail
• Rollback to previous thresholds if needed