feat: Add RPC support for epic commands in daemon mode

- Added OpEpicStatus operation to protocol
- Implemented handleEpicStatus() in RPC server
- Added EpicStatus() method to RPC client
- Updated epic.go to use daemon RPC when available
- Server-side filtering for close-eligible reduces RPC payload
- Both 'bd epic status' and 'bd epic close-eligible' now work in daemon mode

Fixes #62
Closes bd-87

Amp-Thread-ID: https://ampcode.com/threads/T-44c6044e-de04-40a0-bac3-b26238c32a17
Co-authored-by: Amp <amp@ampcode.com>

internal/rpc/server.go

@@ -648,6 +648,8 @@ func (s *Server) handleRequest(req *Request) Response {
 		resp = s.handleExport(req)
 	case OpImport:
 		resp = s.handleImport(req)
+	case OpEpicStatus:
+		resp = s.handleEpicStatus(req)
 	default:
 		s.metrics.RecordError(req.Operation)
 		return Response{
@@ -2212,3 +2214,53 @@ func (s *Server) handleImport(req *Request) Response {
 		Error:   "import via daemon not yet implemented, use --no-daemon flag",
 	}
 }
+
+func (s *Server) handleEpicStatus(req *Request) Response {
+	var epicArgs EpicStatusArgs
+	if err := json.Unmarshal(req.Args, &epicArgs); err != nil {
+		return Response{
+			Success: false,
+			Error:   fmt.Sprintf("invalid epic status args: %v", err),
+		}
+	}
+
+	store, err := s.getStorageForRequest(req)
+	if err != nil {
+		return Response{
+			Success: false,
+			Error:   fmt.Sprintf("storage error: %v", err),
+		}
+	}
+
+	ctx := s.reqCtx(req)
+	epics, err := store.GetEpicsEligibleForClosure(ctx)
+	if err != nil {
+		return Response{
+			Success: false,
+			Error:   fmt.Sprintf("failed to get epic status: %v", err),
+		}
+	}
+
+	if epicArgs.EligibleOnly {
+		filtered := []*types.EpicStatus{}
+		for _, epic := range epics {
+			if epic.EligibleForClose {
+				filtered = append(filtered, epic)
+			}
+		}
+		epics = filtered
+	}
+
+	data, err := json.Marshal(epics)
+	if err != nil {
+		return Response{
+			Success: false,
+			Error:   fmt.Sprintf("failed to marshal epics: %v", err),
+		}
+	}
+
+	return Response{
+		Success: true,
+		Data:    data,
+	}
+}