replace log.Fatal/os.Exit with error returns (#941)

* Use stdlib encoders
* Reduce some duplication
* Remove global pagination state
* Dedupe JSON detail types
* Bump golangci-lint

Reviewed-on: https://gitea.com/gitea/tea/pulls/941
Co-authored-by: techknowlogick <techknowlogick@gitea.com>
Co-committed-by: techknowlogick <techknowlogick@gitea.com>

cmd/flags/generic_test.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"testing"
 
+	"code.gitea.io/sdk/gitea"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/urfave/cli/v3"
@@ -123,3 +124,29 @@ func TestPaginationFailures(t *testing.T) {
 		})
 	}
 }
+
+func TestGetListOptionsDoesNotLeakBetweenCommands(t *testing.T) {
+	var results []gitea.ListOptions
+
+	run := func(args []string) {
+		t.Helper()
+
+		cmd := cli.Command{
+			Name: "test-paging",
+			Action: func(_ context.Context, cmd *cli.Command) error {
+				results = append(results, GetListOptions(cmd))
+				return nil
+			},
+			Flags: PaginationFlags,
+		}
+
+		require.NoError(t, cmd.Run(context.Background(), args))
+	}
+
+	run([]string{"test", "--page", "5", "--limit", "10"})
+	run([]string{"test"})
+
+	require.Len(t, results, 2)
+	assert.Equal(t, gitea.ListOptions{Page: 5, PageSize: 10}, results[0])
+	assert.Equal(t, gitea.ListOptions{Page: defaultPageValue, PageSize: defaultLimitValue}, results[1])
+}