feat(server): org-scope service layer + handlers + org admin API

Threads org_id through every admin-facing service function (servers, keys,
assignments, secrets, workflows/steps/runs, monitors, channels, audit),
adds RequireRole middleware, and wires /api/org user + OIDC management
routes. Agent/scheduler paths keep unique-key signatures and resolve org
from the loaded record; internal-only helpers (getServerByID,
getRunByID, getMonitorByID) preserve those call sites.

server/internal/grpc/server.go

@@ -63,13 +63,13 @@ func (s *vantageServer) UploadGeneratedKey(ctx context.Context, req *pb.UploadKe
 	}
 
 	// Agent-generated keys carry no passphrase over the wire (proto has no field).
-	key, err := services.CreateKey(req.Label, req.PublicKey, "generated", srv.ServerID, req.PrivateKey, "")
+	key, err := services.CreateKey(srv.OrgID, req.Label, req.PublicKey, "generated", srv.ServerID, req.PrivateKey, "")
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "failed to store key: %v", err)
 	}
 
 	// Auto-assign to the generating server
-	if _, err := services.AssignKey(key.KeyID, srv.ServerID); err != nil {
+	if _, err := services.AssignKey(srv.OrgID, key.KeyID, srv.ServerID); err != nil {
 		log.Printf("failed to auto-assign generated key: %v", err)
 	}