GPS Compass: tighten the satellite meter, drop the now-pointless hint

The meter sat too far from the count: the reserve used text_w's
0.55-per-character estimate, which is for mixed text, while the digits and
spaces in "99 sats" run nearer 0.39 of the line height. Sized properly it now
sits beside the number, and still holds still as the count changes.

"A set north" is no longer advertised. The axis mapping is measured, so a
calibrated device points north on its own; A and F remain for an unknown
board or a stubborn environment, they just do not need to be on screen.

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

deploy/apps/gpscompass/1.0/gpscompass.lua

@@ -651,11 +651,12 @@ function app.on_open(w, h)
     label(name, valx, y, 12, C.text, valw)   -- key-less rows line up with the values
     if name == "alt" or name == "spd" then row_hit[name] = { y = y, h = line } end
     if name == "fix" then
-      -- The meter sits right after the count, not out at the column edge —
-      -- the reserve is sized for the widest text ("99 sats") so the bars hold
-      -- still as the number changes.
-      local gap = math.floor(TH12 * 0.45)
-      local sats_x = valx + text_w("99 sats", TH12) + gap
+      -- The meter sits right after the count. The reserve is sized for the
+      -- widest text ("99 sats") so the bars hold still as the number changes,
+      -- but measured properly: text_w's 0.55-per-character estimate is for
+      -- mixed text, while digits and spaces in Montserrat run nearer 0.39 of
+      -- the line height, which left an obvious gap.
+      local sats_x = valx + math.floor(TH12 * 2.8) + 4
       SATS_W = math.max(20, math.min(52, valx + valw - sats_x - 2))
       sats_cv = ui.canvas(SATS_W, SATS_H)
       sats_cv:pos(sats_x, y + math.floor((TH12 - SATS_H) / 2))
@@ -683,9 +684,10 @@ function app.on_open(w, h)
   L.hint = ui.label("", 0, hint_y or (y + 2), 12, C.sub)
   L.hint:width(w, "center")
   if caps.keyboard then
-    local wide = w >= TH12 * 20                 -- room for the target hint too
-    set_text("hint", has_compass and (wide and "C calibrate   A set north   up/down + OK units   <> target"
-                                              or "C calibrate   A north   OK units   <> target")
+    -- "A set north" is deliberately not advertised: the axis mapping is
+    -- measured, so a calibrated device points north on its own. A (and F)
+    -- still work for an unknown board or a stubborn environment.
+    set_text("hint", has_compass and "C calibrate   up/down + OK units   <> target"
                                   or "up/down + OK units   <> target", C.sub)
   elseif caps.touch then
     set_text("hint", "Tap a row for units, the dial for the next target", C.sub)