Status blocks replace the spinner: blue breathing / green / red

ui_quiet_run now paints a TTY-safe status BLOCK: a background-coloured
SPACE (never a glyph, no font/locale dependency — the braille lesson).

  busy : blue block breathing through a 256-colour ramp (48;5;17..33)
         with the live dnf action after it
  ok   : solid green block + package count
  fail : solid RED block (spec: YuKu changed the red X to a red block)
         followed by the log tail

Colour-depth aware: 256-colour ramp -> 16-colour blue/bright-blue ->
plain ASCII spinner when the terminal reports no colour. LANG=C pty
run shows zero non-ASCII bytes.

Also vendors lib/ui-block.sh (the standalone helper from the Telegram
session prototype; fail changed to red block) and installs the
ui_block_close EXIT trap — with a return 0, because an EXIT trap's
status becomes the script's exit code (harness caught every-successful-
run exiting 1 through that path).

setup.sh

@@ -12,6 +12,10 @@ source "$SCRIPT_DIR/lib/common.sh"
 source "$SCRIPT_DIR/lib/session.sh"
 # shellcheck source=lib/ui.sh
 source "$SCRIPT_DIR/lib/ui.sh"
+# shellcheck source=lib/ui-block.sh
+source "$SCRIPT_DIR/lib/ui-block.sh"
+# never leave a block pulse loop running if the script is interrupted
+trap 'ui_block_close' EXIT INT TERM
 
 # Full dnf output from quiet transactions lands here (shown on failure).
 export SETUP_DNF_LOG="${SETUP_DNF_LOG:-/tmp/fedora-setup-dnf-$(id -u).log}"