fix(cockpit): an application subject keeps its rates on a slow update interval, its ground lift eases out, and its HUD shows a speed and a progress name only when given

An application subject's camera step is now capped at its own update
interval plus 0.1 s rather than at 0.1 s, so at 500 ms its heading slew,
ground lift and anchor correction run at their configured rates; a long
stall still moves it no further than one late update. The built-in
views keep their 0.1 s cap.

When groundClamp turns false the lift the floor gave goes at the rate
it came, not at once. A HUD view with no speed has no speed readout,
and a progress line with no summary is hidden from assistive
technology instead of being an unnamed image.

src/cockpitMath.test.mjs

@@ -8,6 +8,7 @@ import {
   cockpitAnchorCorrectionStep,
   cockpitAltitudeDisplayFt,
   cockpitGroundSafeHeight,
+  cockpitSubjectStepSec,
   cockpitSurfaceWaitExpired,
   cockpitUiUpdateDue,
   COCKPIT_SUBJECT_LIFT_MPS,
@@ -58,6 +59,28 @@ test('cockpit anchor correction bounds late-fix catch-up and render stalls', ()
   assert.equal(cockpitAnchorCorrectionStep(Number.NaN, 250, 0.1), 0);
 });
 
+test('an application subject on a slow cadence is corrected for its whole step', () => {
+  // The built-in views' step stays capped at 0.1 s...
+  const capped = cockpitAnchorCorrectionStep(100, 0, 0.5);
+  assert.equal(capped, cockpitAnchorCorrectionStep(100, 0, 0.1));
+  // ...while a subject updated every 500 ms is corrected for all of it.
+  const whole = cockpitAnchorCorrectionStep(100, 0, 0.5, 0.5);
+  assert.ok(Math.abs(whole / capped - 5) < 1e-9);
+  assert.equal(cockpitAnchorCorrectionStep(100, 0, 0.5, Number.NaN), capped);
+});
+
+test('an application subject steps by its interval, never by a long stall', () => {
+  assert.equal(cockpitSubjectStepSec(16, 0), 0.016);
+  assert.equal(cockpitSubjectStepSec(500, 500), 0.5);
+  assert.equal(cockpitSubjectStepSec(520, 500), 0.52);
+  // A hidden tab's minutes count as one late update.
+  assert.equal(cockpitSubjectStepSec(60_000, 500), 0.6);
+  assert.equal(cockpitSubjectStepSec(60_000, 0), 0.1);
+  assert.equal(cockpitSubjectStepSec(-5, 500), 0);
+  assert.equal(cockpitSubjectStepSec(Number.NaN, 500), 0);
+  assert.equal(cockpitSubjectStepSec(1000, Number.NaN), 0.1);
+});
+
 test('cockpit camera clearance never falls below the rendered ground floor', () => {
   assert.equal(cockpitGroundSafeHeight(47, 57, 12), 69);
   assert.equal(cockpitGroundSafeHeight(1200, 57, 12), 1200);