feat: fit list tables to the terminal and write TSV when piped

Lists had no header, wrapped every row once a title was longer than
the terminal, and were space-padded when piped, so cut -f and awk -F'\t'
could not split them and empty cells collapsed.

terminal.Table now takes column specs and a Display. On a terminal it
prints an uppercase header, aligns columns two spaces apart and shrinks
flexible columns, widest first, to Streams.Width (the terminal, then
$COLUMNS, then 80), cutting by display width with "…". States use the
terminal's ANSI 16 colors, hex colors fall back to the 256-color palette
unless COLORTERM advertises 24-bit, and OSC 8 links appear only on the
first column, independently of color (TEA_HYPERLINKS=auto|always|never).
Piped tables are tab-separated without header, color or links, and times
are RFC3339 UTC instead of "about 2 hours ago".

terminal.View lays out single resources (title, badges, metadata, fields,
body, footer URL) and renders markdown bodies with glamour on a terminal
only (TEA_MARKDOWN=raw keeps them raw). Shared formatters cover relative
times, timestamps, sizes, durations and status icons.

In the app, writeTable and writeView are the new list and view writers:
a "Showing N of M …" context line, an empty-state message on stderr and
the next-page hint. writeList, writeItem and batch keep working and now
render through the new table: tab-separated when piped, truncated at the
widest column on a terminal, with headers for issue list and pr list.

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

internal/terminal/format_test.go

@@ -0,0 +1,67 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package terminal
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRelativeTime(t *testing.T) {
+	now := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
+	for _, tc := range []struct {
+		at   time.Time
+		want string
+	}{
+		{now.Add(-30 * time.Second), "less than a minute ago"},
+		{now.Add(-time.Minute), "about 1 minute ago"},
+		{now.Add(-3 * time.Hour), "about 3 hours ago"},
+		{now.AddDate(0, -2, 0), "about 2 months ago"},
+		{now.AddDate(-2, -1, 0), "about 2 years ago"},
+		{now.Add(10 * time.Second), "in less than a minute"},
+		{now.AddDate(0, 0, 3), "in about 3 days"},
+	} {
+		require.Equal(t, tc.want, RelativeTime(now, tc.at), tc.at)
+	}
+}
+
+func TestTimestamp(t *testing.T) {
+	at := time.Date(2026, 10, 11, 20, 48, 23, 588823137, time.FixedZone("CEST", 2*3600))
+	require.Equal(t, "2026-10-11T18:48:23Z", Timestamp(at))
+	require.Equal(t, at.Unix(), ParseTime("2026-10-11T20:48:23+02:00").Unix())
+	require.True(t, ParseTime("").IsZero())
+	require.True(t, ParseTime("yesterday").IsZero())
+}
+
+func TestBytes(t *testing.T) {
+	for n, want := range map[int64]string{0: "0 B", 13: "13 B", 1023: "1023 B", 1536: "1.5 KiB", 3040870: "2.9 MiB", 5 << 30: "5.0 GiB", 3 << 50: "3072.0 TiB"} {
+		require.Equal(t, want, Bytes(n), n)
+	}
+}
+
+func TestDuration(t *testing.T) {
+	for d, want := range map[time.Duration]string{0: "0s", 45 * time.Second: "45s", 72 * time.Second: "1m 12s", 90 * time.Minute: "1h 30m", 2 * time.Hour: "2h 0m", 1499 * time.Millisecond: "1s"} {
+		require.Equal(t, want, Duration(d), d)
+	}
+}
+
+func TestStatusIcon(t *testing.T) {
+	for _, tc := range []struct {
+		status, conclusion string
+		want               Cell
+	}{
+		{"completed", "success", Cell{Text: "✓", Color: "green"}},
+		{"success", "", Cell{Text: "✓", Color: "green"}},
+		{"completed", "failure", Cell{Text: "X", Color: "red"}},
+		{"error", "", Cell{Text: "X", Color: "red"}},
+		{"completed", "cancelled", Cell{Text: "-", Muted: true}}, //nolint:misspell // Gitea API spelling.
+		{"skipped", "", Cell{Text: "-", Muted: true}},
+		{"queued", "", Cell{Text: "*", Color: "yellow"}},
+		{"pending", "", Cell{Text: "*", Color: "yellow"}},
+	} {
+		require.Equal(t, tc.want, StatusIcon(tc.status, tc.conclusion), "%s/%s", tc.status, tc.conclusion)
+	}
+}