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/streams.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strconv"
 	"strings"
 
 	"charm.land/huh/v2"
@@ -24,11 +25,29 @@ type Streams struct {
 	InTTY  bool
 	OutTTY bool
 	ErrTTY bool
+	// Width is the number of columns human output on Out fits in; 0 means unlimited.
+	Width int
 }
 
 // System binds streams to the current process and detects each terminal.
 func System() Streams {
-	return Streams{In: os.Stdin, Out: os.Stdout, ErrOut: os.Stderr, InTTY: term.IsTerminal(int(os.Stdin.Fd())), OutTTY: term.IsTerminal(int(os.Stdout.Fd())), ErrTTY: term.IsTerminal(int(os.Stderr.Fd()))}
+	return Streams{
+		In: os.Stdin, Out: os.Stdout, ErrOut: os.Stderr,
+		InTTY: term.IsTerminal(int(os.Stdin.Fd())), OutTTY: term.IsTerminal(int(os.Stdout.Fd())), ErrTTY: term.IsTerminal(int(os.Stderr.Fd())),
+		Width: terminalWidth(int(os.Stdout.Fd()), os.Getenv),
+	}
+}
+
+// terminalWidth returns the width of the terminal at fd, then $COLUMNS, then 80. A pty without a
+// window size, such as `script` run without a terminal, reports a width of 0.
+func terminalWidth(fd int, getenv func(string) string) int {
+	if width, _, err := term.GetSize(fd); err == nil && width > 0 {
+		return width
+	}
+	if width, err := strconv.Atoi(getenv("COLUMNS")); err == nil && width > 0 {
+		return width
+	}
+	return 80
 }
 
 // Policy controls input interaction independently of supplied flag count.