Show what a run is doing, and record when one is cut short

A run that held back a blocker then upgraded 214 packages printed one line and
then nothing for nearly five minutes while pacman downloaded and installed. It
looked hung, so it got killed - during pacman's uninterruptible commit phase,
which meant the packages landed but our bookkeeping never did. The menu then
kept showing a failure from a previous run on a fully up-to-date machine.

pacman, the AUR helper and flatpak now stream their output when a person is
watching, and the progress bar is left enabled for that case. Timer runs are
unchanged: quiet, --noprogressbar, everything captured in the log.

Interactivity is decided once at startup rather than tested at the point of
use. cau_pacman_flags runs inside a process substitution, so its stdout is
always a pipe and a -t 1 check there would have silently always been false.

INT/TERM/HUP now record last_result=interrupted, so a run that is stopped says
so instead of leaving the previous verdict standing.

Makefile

@@ -8,7 +8,7 @@
 # Overridable so a packager can pass the version it is actually building
 # (`make VERSION=$pkgver`). The literal below is the fallback for builds
 # straight from a checkout, and is what a release tag has to carry.
-VERSION      ?= 1.0.5
+VERSION      ?= 1.0.6
 
 PREFIX       ?= /usr
 DESTDIR      ?=