feat: auth user feedbacks

internal/model/feedback.go

@@ -31,6 +31,13 @@ type Feedback struct {
 	// resolve is a no-op.
 	ResolvedAt   *time.Time `json:"resolved_at,omitempty"`
 
+	// ReplyMessage is the admin's written reply to the submitter, sent
+	// (and stored) from the admin panel. NULL until an admin replies.
+	// RepliedAt stamps when it was sent. Surfaced to the submitter on the
+	// "My feedback" page as the team's response.
+	ReplyMessage *string    `json:"reply_message,omitempty"`
+	RepliedAt    *time.Time `json:"replied_at,omitempty"`
+
 	AuthorHandle *string `json:"author_handle,omitempty"`
 	AuthorName   *string `json:"author_name,omitempty"`
 	AuthorEmail  *string `json:"-"` // server-side only; never serialised