feat: implement system prompt builder with modes, tiers, and providers

- Added a system prompt builder to create dynamic prompts based on different modes (ask, code review, composer, debug, implement, plan, refactor).
- Introduced prompt tiers (balanced, fast, thorough) to tailor responses based on user needs
- Integrated multiple AI providers (Anthropic, Copilot, Google, Ollama, OpenAI) for flexible backend support.
- Updated agent and multi-agent services to utilize the new prompt system.

.gitignore

@@ -6,7 +6,7 @@
 # Node + TypeScript (generated via gitignore.io)
 
 # Logs
-logs
+#logs
 *.log
 npm-debug.log*
 yarn-debug.log*