feat(rpc): enrich MutationEvent with Title and Assignee fields

Add Title and Assignee fields to MutationEvent struct so activity feeds
can display meaningful context without extra lookups. Updated emitMutation
signature to accept these values and modified all callers:

- Create: passes issue.Title and issue.Assignee directly
- Update/Close: moved emitMutation after GetIssue to access enriched data
- Delete: uses existing issue lookup before deletion
- Dep/Label/Comment ops: passes empty strings (would require extra lookup)

Fixes bd-gqxd

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

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

internal/rpc/server_issues_epics.go

@@ -350,7 +350,7 @@ func (s *Server) handleCreate(req *Request) Response {
 	}
 
 	// Emit mutation event for event-driven daemon
-	s.emitMutation(MutationCreate, issue.ID)
+	s.emitMutation(MutationCreate, issue.ID, issue.Title, issue.Assignee)
 
 	data, _ := json.Marshal(issue)
 	return Response{
@@ -470,11 +470,13 @@ func (s *Server) handleUpdate(req *Request) Response {
 			s.emitRichMutation(MutationEvent{
 				Type:      MutationStatus,
 				IssueID:   updateArgs.ID,
+				Title:     issue.Title,
+				Assignee:  issue.Assignee,
 				OldStatus: string(issue.Status),
 				NewStatus: *updateArgs.Status,
 			})
 		} else {
-			s.emitMutation(MutationUpdate, updateArgs.ID)
+			s.emitMutation(MutationUpdate, updateArgs.ID, issue.Title, issue.Assignee)
 		}
 	}
 
@@ -544,6 +546,8 @@ func (s *Server) handleClose(req *Request) Response {
 	s.emitRichMutation(MutationEvent{
 		Type:      MutationStatus,
 		IssueID:   closeArgs.ID,
+		Title:     issue.Title,
+		Assignee:  issue.Assignee,
 		OldStatus: oldStatus,
 		NewStatus: "closed",
 	})
@@ -640,7 +644,7 @@ func (s *Server) handleDelete(req *Request) Response {
 		}
 
 		// Emit mutation event for event-driven daemon
-		s.emitMutation(MutationDelete, issueID)
+		s.emitMutation(MutationDelete, issueID, issue.Title, issue.Assignee)
 		deletedCount++
 	}
 
@@ -1421,7 +1425,7 @@ func (s *Server) handleGateCreate(req *Request) Response {
 	}
 
 	// Emit mutation event
-	s.emitMutation(MutationCreate, gate.ID)
+	s.emitMutation(MutationCreate, gate.ID, gate.Title, gate.Assignee)
 
 	data, _ := json.Marshal(GateCreateResult{ID: gate.ID})
 	return Response{
@@ -1702,7 +1706,7 @@ func (s *Server) handleGateWait(req *Request) Response {
 		}
 
 		// Emit mutation event
-		s.emitMutation(MutationUpdate, gateID)
+		s.emitMutation(MutationUpdate, gateID, gate.Title, gate.Assignee)
 	}
 
 	data, _ := json.Marshal(GateWaitResult{AddedCount: addedCount})