feat(api): add OpenClawGatewayModule with agent registry (MS22-P1b)

apps/api/prisma/migrations/20260301075200_add_openclaw_agent_registry/migration.sql

@@ -0,0 +1,18 @@
+-- CreateTable
+CREATE TABLE "OpenClawAgent" (
+    "id" TEXT NOT NULL,
+    "name" TEXT NOT NULL,
+    "displayName" TEXT NOT NULL,
+    "role" TEXT NOT NULL,
+    "gatewayUrl" TEXT NOT NULL,
+    "agentId" TEXT NOT NULL DEFAULT 'main',
+    "model" TEXT NOT NULL,
+    "isActive" BOOLEAN NOT NULL DEFAULT true,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "OpenClawAgent_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "OpenClawAgent_name_key" ON "OpenClawAgent"("name");