feat(ms22-p2): add agent status endpoints and chat routing (#684)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/api/src/chat-proxy/chat-proxy.dto.ts

@@ -1,5 +1,12 @@
 import { Type } from "class-transformer";
-import { ArrayMinSize, IsArray, IsNotEmpty, IsString, ValidateNested } from "class-validator";
+import {
+  ArrayMinSize,
+  IsArray,
+  IsNotEmpty,
+  IsOptional,
+  IsString,
+  ValidateNested,
+} from "class-validator";
 
 export interface ChatMessage {
   role: string;
@@ -22,4 +29,8 @@ export class ChatStreamDto {
   @ValidateNested({ each: true })
   @Type(() => ChatMessageDto)
   messages!: ChatMessageDto[];
+
+  @IsString({ message: "agent must be a string" })
+  @IsOptional()
+  agent?: string;
 }