fix: migration

internal/service/sadhna_service.go

@@ -94,6 +94,11 @@ const fallbackTZ = "Asia/Kolkata"
 // genuine UTC user re-reports their real zone on next load.
 func (s *SadhnaService) resolveTZ(ctx context.Context, userID string) (string, *time.Location) {
 	tz, _ := s.logs.UserTimezone(ctx, userID)
+	// Canonicalize legacy aliases (e.g. stored "Asia/Calcutta") — the name
+	// is fed into SQL AT TIME ZONE, which rejects aliases on a Postgres
+	// without the tzdata backward links. Covers rows written before
+	// SetTimezone started canonicalizing.
+	tz = canonicalTZ(tz)
 	if tz == "" || tz == "UTC" {
 		tz = fallbackTZ
 	}