refactor(services): leave CLI flag and command names to the app layer

Services report ErrRunScanExhausted, ErrMaxPages and plain conflicts,
and the commands add the --branch/--max-pages/--force hints. Unknown
label names use the shared NotFoundError, and the repository-scoped
review and team search refusal moves into tea search's own usage
check.

Signed-off-by: bircni <bircni@icloud.com>

internal/app/labels.go

@@ -182,7 +182,7 @@ $ tea label create bug -c ee0701 --force`, Args: usageArgs(cobra.MaximumNArgs(1)
 		}
 		item, updated, err := s.CreateUnique(cmd.Context(), existing, opts, force)
 		if err != nil {
-			return err
+			return forceHint(err)
 		}
 		return a.reportLabel(cmd, s, item, updated)
 	}}
@@ -220,6 +220,14 @@ func (a *application) askLabelDetails(cmd *cobra.Command, opts *services.LabelOp
 	return nil
 }
 
+// forceHint points at --force when a label exists already.
+func forceHint(err error) error {
+	if conflict, ok := errors.AsType[*services.ConflictError](err); ok && conflict.Reason == services.ReasonExists {
+		conflict.Hint = "pass --force to update it"
+	}
+	return err
+}
+
 // reportLabel reports a created or updated label as JSON or with a ✓ line.
 func (a *application) reportLabel(cmd *cobra.Command, s services.Labels, item services.Label, updated bool) error {
 	verb := "Created"
@@ -336,6 +344,7 @@ func (a *application) createLabels(cmd *cobra.Command, s services.Labels, rows [
 	outcome := map[string]string{}
 	results, failures := applyBatch(cmd, rows, func(row services.LabelOptions) string { return "label " + strconv.Quote(*row.Name) }, func(row services.LabelOptions) (services.Label, error) {
 		item, updated, err := s.CreateUnique(cmd.Context(), existing, row, force)
+		err = forceHint(err)
 		switch {
 		case err != nil:
 			return item, err