Make the run switch a switch, and split the tuning tolerance by mode

Three things you could not see or could not set.

Run and S&P were a label saying which one you were in. They are two buttons
now, the one you are in marked, either one clickable, which is what N1MM has.
Ctrl+? and F1 still work.

The tuning tolerance is one number per mode, as N1MM keeps it: CW, phone and
digital, 300 Hz each, which are its defaults. A phone signal is wide and a CW
one is not, so one number for both was wrong.

The bearing line went blank whenever it could not be worked out, which looks
exactly like a missing feature. It now says which end could not be placed and
what to do — no country file, no position for your own station, or a callsign
the country file does not place. It also gives miles beside the kilometres, as
N1MM does.

While clicking it: a marked button lost its mark under the pointer, because the
theme paints its own background there. The band buttons had the same fault.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -198,8 +198,11 @@ name and the comment — and round again; shift and tab go the other way. N1MM
 does not touch the tab key at all, so tab there walks its boxes in the order
 they are laid out, which is what this does.
 
-Two lights sit beside the run switch: the left one is green while a radio is
-answering, the right one red while something is going out on the air.
+Run and S&P are two buttons beside the lights; the one you are in is marked.
+Ctrl+? switches between them, and F1 puts you into run mode, as in N1MM.
+
+Two lights sit beside them: the left one is green while a radio is answering,
+the right one red while something is going out on the air.
 
 ### The buttons and the title bar
 
@@ -226,14 +229,18 @@ when this is the frequency you last called CQ on. While searching, space with an
 empty callsign box takes the station out of the frame and into the box, so a
 spotted station is worked without typing its call. While running it does not,
 because a running station is answering callers rather than chasing the one it is
-sitting on. How close the radio has to be to a spot is `TuningToleranceHertz` in
-`settings.json`, 300 Hz out of the box, which is N1MM's default.
+sitting on. How close the radio has to be to a spot is one number per mode in
+`settings.json` — `CwTuningToleranceHertz`, `PhoneTuningToleranceHertz` and
+`DigitalTuningToleranceHertz` — 300 Hz each out of the box, which is how N1MM
+keeps them and what it defaults them to.
 
 ### Where the other station is
 
 Under the entry window is the line N1MM writes there: the beam heading, the
 heading the long way round, the distance in kilometres, and the sunrise and
-sunset times at the other station.
+sunset times at the other station, in kilometres and miles as N1MM shows them.
+When it cannot be worked out the line says which end could not be placed, rather
+than going blank.
 
 The position comes from the grid square when the contest exchanges one and it
 has been copied, or from the call history file, and from the country file