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.

src/interfaces/AgentOptions.ts

@@ -19,4 +19,11 @@ export interface AgentOptions {
   autoApprove?: boolean;
   /** Chat mode - only read-only tools, no file modifications */
   chatMode?: boolean;
+  /** Model-specific parameters from tier detection */
+  modelParams?: {
+    temperature?: number;
+    topP?: number;
+    topK?: number;
+    maxTokens?: number;
+  };
 }