fix(awareness): show a 999.6 m contact as 1.0 km, not 1000 m (#1387)

Choose awareness distance units after rounding so nearby contacts never display as 1000 metres.

Contribution by @rudycelekli.

changelog.d/1387-awareness-distance-kilometre.md

@@ -0,0 +1,3 @@
+- Show a Contacts entry 999.5 m or more away as 1.0 km. The panel kept meters
+  below 1000, then rounded 999.6 m up to "1000 m"
+  (Rudy Celekli, @rudycelekli, #1387).

docs/CURRENT-STATE.md

@@ -4370,6 +4370,9 @@ silent for five minutes are removed. Credits appear when the feed is used.
 coordinator, but it is not a user-visible Data Layers entry. Its visible entry
 point is the right-side `CONTEXT` chooser's `CONTACTS` mode.
 
+Contacts distance labels select metres or kilometres after rounding to the
+nearest metre, so a 999.5-metre contact displays as `1.0 km`, not `1000 m`.
+
 At global scale, ambient Radio cluster badges are hard-opacity shared-host
 entries: count/category updates and identity replacement do not run keyhole or
 enter/exit ramps. Shared collision, viewport rejection, allocation, and horizon

src/data/militaryAwareness.test.mjs

@@ -42,7 +42,10 @@ import {
   formatAwarenessLabel,
   getAwarenessNavigationTargets,
 } from './militaryAwarenessEngine.js';
-import { formatAwarenessCount } from '../layers/awareness/panel.js';
+import {
+  formatAwarenessCount,
+  presentAwarenessDistance,
+} from '../layers/awareness/panel.js';
 import { NAVIGATION_AUTHORITY_EVENT } from '../navigationPolicy.js';
 
 const militaryAwarenessSource = readLayerSource(
@@ -69,6 +72,12 @@ test('Contacts labels a capped cohort as a lower bound', () => {
   assert.equal(formatAwarenessCount({ count: null }), '?');
 });
 
+test('Contacts moves a distance that rounds to 1,000 m into kilometres', () => {
+  assert.equal(presentAwarenessDistance(999.4), '999\u00a0m');
+  assert.equal(presentAwarenessDistance(999.6), '1.0\u00a0km');
+  assert.equal(presentAwarenessDistance(4600), '4.6\u00a0km');
+});
+
 function installAwarenessRuntime({
   isEnabled = () => true,
   isEffectivelyEnabled = isEnabled,

src/layers/awareness/panel.js

@@ -25,9 +25,10 @@ function presentAwarenessCount(summary = {}) {
 }
 
 /** A distance as the panel shows it: 850 m, 4.6 km, 120 km, in the UI language. */
-function presentAwarenessDistance(meters) {
+export function presentAwarenessDistance(meters) {
   if (!Number.isFinite(meters) || meters < 0) return '—';
-  if (meters < 1000) return formatQuantity(Math.round(meters), 'm');
+  const wholeMeters = Math.round(meters);
+  if (wholeMeters < 1000) return formatQuantity(wholeMeters, 'm');
   const digits = meters < 10000 ? 1 : 0;
   return formatQuantity(meters / 1000, 'km', {
     minimumFractionDigits: digits,