Add default conversation title

internal/service/conversations.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 	"unicode/utf8"
 
+	"code.chimeric.al/chimerical/odidere/internal/conversation"
 	"code.chimeric.al/chimerical/odidere/internal/db"
 )
 
@@ -129,17 +130,12 @@ func (svc *Service) getConversationHandler(
 	}
 }
 
-// maxTitleLength is the most characters, counted as Unicode code
-// points, that a conversation title may hold. It keeps a title
-// short enough for the picker and small in storage.
-const maxTitleLength = 256
-
 // updateConversation renames one conversation. The handler trims
 // the title, then rejects an empty title or a title longer than
-// maxTitleLength with 400. A conversation that does not exist, or
-// belongs to another user, returns 404. The rename is allowed while
-// inference runs: a title is not a message, and a concurrent
-// inference does not read or write it.
+// conversation.MaxTitleLength with 400. A conversation that does
+// not exist, or belongs to another user, returns 404. The rename
+// is allowed while inference runs: a title is not a message, and a
+// concurrent inference does not read or write it.
 func (svc *Service) updateConversation(w http.ResponseWriter, r *http.Request) {
 	var (
 		ctx = r.Context()
@@ -165,7 +161,7 @@ func (svc *Service) updateConversation(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "invalid request", http.StatusBadRequest)
 		return
 	}
-	if utf8.RuneCountInString(req.Title) > maxTitleLength {
+	if utf8.RuneCountInString(req.Title) > conversation.MaxTitleLength {
 		http.Error(w, "invalid request", http.StatusBadRequest)
 		return
 	}