* qc: interactive by default, drop qc-report

faba qc now opens the site-threshold view unless --batch-process is given,
and stops with an error when there is no terminal to show it on.
qc-report and -I/--interactive are removed.

In the view, Tab moves between the thresholds panel and the gene list,
and the arrow keys drive the panel in focus; m switches modality.
Shift+Enter (or A, where the terminal cannot report Shift+Enter) opens a
confirmation pop-up, and plain Enter no longer applies. Once confirmed,
the fileset is written on a thread with a progress pop-up over the view.

Run with no input or -o, qc asks for them first in a directory browser
pop-up. The printed command (p) is a full --batch-process command.

* qc view: one series per plot, genes by kept sites, figures with the cut

The gene and metagene panels draw the kept sites only; the gene title and
the metagene's region line still give kept / all. The gene list is ordered
by kept sites and re-sorted as the thresholds move, with --genes pinned
first and the selection kept on its gene.

Applying the thresholds also saves the view's figure for every modality
and knob, as set at that moment, to qc_plots/ in the new fileset.

* qc view: draw the figures off the key press, never fail the write on one

The figures are drawn on the tick after the confirmation, under the
writing pop-up, rather than in the key handler. They are saved after
qc_summary.tsv, and a figure that fails to save only warns. The gene
filter no longer decides which gene the other modalities' figures show.