Add Agent capabilities and configurations across the application

- Extend the AssistantConfig model to include agent_interface_type, agent_values, and agent_secrets for enhanced agent management.
- Update ModelType to include "Agent" for broader capability support.
- Seed new agent models and configurations in the database for Dify, FastGPT, and OpenCode applications.
- Modify the Assistant routes to validate and handle agent capabilities.
- Implement agent resource resolution in the config resolver for runtime configuration.
- Enhance the interface catalog with agent-specific fields and definitions.
- Update frontend components to manage agent configurations, including form handling and state management for agent-related inputs.

frontend/src/lib/api.ts

@@ -8,7 +8,7 @@
 export const API_BASE =
   process.env.NEXT_PUBLIC_API_BASE_URL ?? "http://localhost:8000";
 
-export type ModelType = "LLM" | "ASR" | "TTS" | "Realtime" | "Embedding";
+export type ModelType = "LLM" | "ASR" | "TTS" | "Realtime" | "Embedding" | "Agent";
 async function request<T>(path: string, init?: RequestInit): Promise<T> {
   const res = await fetch(`${API_BASE}${path}`, {
     headers: { "Content-Type": "application/json" },