i18n(ja): apply review round 2

Catalog fixes from the second review round (squawk 7600/7700 names,
transit occupancy, radio category, cyclone advisory wording, Orbital Watch,
validation and hint texts), cockpit distances keep "km" in Japanese as in
Chinese, the CCTV context line uses the translated view band, and the
Japanese layer status line no longer splits "1分以内".

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/i18n/ja-display.test.mjs

@@ -0,0 +1,21 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { setLocale } from './index.js';
+import {
+  cockpitUnitCase,
+  formatCockpitDistance,
+} from '../ui/cockpitPresentation.js';
+
+test('Japanese cockpit distances keep the unit in its own case', () => {
+  try {
+    setLocale('ja');
+    assert.equal(formatCockpitDistance(14000), '14 km');
+    assert.equal(formatCockpitDistance(9500), '9.5 km');
+    assert.equal(cockpitUnitCase('km'), 'km');
+    setLocale('en');
+    assert.equal(formatCockpitDistance(14000), '14 KM');
+    assert.equal(cockpitUnitCase('km'), 'KM');
+  } finally {
+    setLocale('en');
+  }
+});