Resolve merge conflicts in AI Chat configuration management

- AgentNodes.ts: Keep LLMConfigurationManager approach for centralized config handling
- EvaluationAgent.ts: Keep configManager scope for proper cleanup in finally block
- AgentService.ts: Remove duplicate static method/property definitions

The conflicts were between centralized configuration management (HEAD) and
individual parameter passing (upstream/main). The centralized approach is
kept for better override support during evaluations.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: olesho