refactor: remove features beyond the UX plan

Drop additions that the UX plan does not ask for:

- the interactive label edit form; label edit now requires a flag
- label clone and the skip mode of label creation it needed
- repo rename rewriting the Git remote or tea.repository; it now
  warns that the remote still points to the old name
- the extra "source" remote on clones of pull mirrors
- run artifact download, which duplicates run download --zip
- 256-color and 24-bit label swatches; colors stay ANSI 16
- config list --show-source (config get keeps it)
- the membership and access GETs before team member/repo add and
  remove; Gitea's PUT and DELETE are idempotent

label edit/delete keep --by-name: it is the only way to address a
label whose name is a number that is also another label's ID.

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

internal/app/human_output.go

@@ -33,13 +33,12 @@ func (a *application) display() terminal.Display {
 	preferences, _ := a.preferences()
 	streams := a.deps.Streams
 	return terminal.Display{
-		TTY:       streams.OutTTY,
-		Color:     terminal.ColorEnabled(preferences.Color, streams.OutTTY, a.deps.Getenv),
-		TrueColor: terminal.TrueColor(a.deps.Getenv),
-		Links:     terminal.HyperlinksEnabled(preferences.Hyperlinks, streams.OutTTY, a.deps.Getenv),
-		Markdown:  terminal.MarkdownEnabled(preferences.Markdown, streams.OutTTY),
-		Width:     streams.Width,
-		Now:       a.deps.Now(),
+		TTY:      streams.OutTTY,
+		Color:    terminal.ColorEnabled(preferences.Color, streams.OutTTY, a.deps.Getenv),
+		Links:    terminal.HyperlinksEnabled(preferences.Hyperlinks, streams.OutTTY, a.deps.Getenv),
+		Markdown: terminal.MarkdownEnabled(preferences.Markdown, streams.OutTTY),
+		Width:    streams.Width,
+		Now:      a.deps.Now(),
 	}
 }