feat(orchestrator): MS23-P0-004 operator inject/pause/resume endpoints (#712)

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

apps/orchestrator/src/api/agents/agent-control.service.ts

@@ -0,0 +1,68 @@
+import { Injectable } from "@nestjs/common";
+import type { Prisma } from "@prisma/client";
+import { PrismaService } from "../../prisma/prisma.service";
+
+@Injectable()
+export class AgentControlService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  private toJsonValue(value: Record<string, unknown>): Prisma.InputJsonValue {
+    return value as Prisma.InputJsonValue;
+  }
+
+  private async createOperatorAuditLog(
+    agentId: string,
+    operatorId: string,
+    action: "inject" | "pause" | "resume",
+    payload: Record<string, unknown>
+  ): Promise<void> {
+    await this.prisma.operatorAuditLog.create({
+      data: {
+        sessionId: agentId,
+        userId: operatorId,
+        provider: "internal",
+        action,
+        metadata: this.toJsonValue({ payload }),
+      },
+    });
+  }
+
+  async injectMessage(agentId: string, operatorId: string, message: string): Promise<void> {
+    const treeEntry = await this.prisma.agentSessionTree.findUnique({
+      where: { sessionId: agentId },
+      select: { id: true },
+    });
+
+    if (treeEntry) {
+      await this.prisma.agentConversationMessage.create({
+        data: {
+          sessionId: agentId,
+          role: "operator",
+          content: message,
+          provider: "internal",
+          metadata: this.toJsonValue({}),
+        },
+      });
+    }
+
+    await this.createOperatorAuditLog(agentId, operatorId, "inject", { message });
+  }
+
+  async pauseAgent(agentId: string, operatorId: string): Promise<void> {
+    await this.prisma.agentSessionTree.updateMany({
+      where: { sessionId: agentId },
+      data: { status: "paused" },
+    });
+
+    await this.createOperatorAuditLog(agentId, operatorId, "pause", {});
+  }
+
+  async resumeAgent(agentId: string, operatorId: string): Promise<void> {
+    await this.prisma.agentSessionTree.updateMany({
+      where: { sessionId: agentId },
+      data: { status: "running" },
+    });
+
+    await this.createOperatorAuditLog(agentId, operatorId, "resume", {});
+  }
+}