Add daemon RPC support for gate commands (bd-likt)

- Add gate operation constants (OpGateCreate, OpGateList, OpGateShow,
  OpGateClose, OpGateWait) to protocol.go
- Add Gate*Args and Gate*Result types to protocol.go
- Add gate handler methods (handleGateCreate, handleGateList,
  handleGateShow, handleGateClose, handleGateWait) to server_issues_epics.go
- Register gate handlers in handleRequest switch
- Add gate client methods (GateCreate, GateList, GateShow, GateClose,
  GateWait) to client.go
- Update cmd/bd/gate.go to use daemon client when available, falling
  back to direct store access

Gate commands now work with the daemon, eliminating the need for
--no-daemon flag.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/rpc/server_routing_validation_diagnostics.go

@@ -221,6 +221,17 @@ func (s *Server) handleRequest(req *Request) Response {
 		resp = s.handleGetMutations(req)
 	case OpShutdown:
 		resp = s.handleShutdown(req)
+	// Gate operations (bd-likt)
+	case OpGateCreate:
+		resp = s.handleGateCreate(req)
+	case OpGateList:
+		resp = s.handleGateList(req)
+	case OpGateShow:
+		resp = s.handleGateShow(req)
+	case OpGateClose:
+		resp = s.handleGateClose(req)
+	case OpGateWait:
+		resp = s.handleGateWait(req)
 	default:
 		s.metrics.RecordError(req.Operation)
 		return Response{