fix(cctv): show a camera facing 359.6° as HDG 0°, not HDG 360°

The CCTV HUD heading token and the camera panel's meta line rounded the
bearing without wrapping, so a camera facing 359.5° or more (a feed
bearing, or a heading calibrated just west of north) read "HDG 360°".
Both now wrap after rounding: 359.6° reads "HDG 0°", 359.4° "HDG 359°".

docs/CURRENT-STATE.md

@@ -4788,7 +4788,9 @@ silently demoting every later lookup for the session.
   wireframe dashed; colours, widths and active/idle emphasis are unchanged. A manual calibration
   (`calSource: 'manual'`) or curated pose (`poseSource: 'curated'`) is never presented as
   estimated, matching the CAL badge. Public camera state carries `headingConfidence` and
-  `headingEstimated` (`src/layers/cctv/headingConfidence.js`, #639).
+  `headingEstimated` (`src/layers/cctv/headingConfidence.js`, #639). The HUD token and the
+  camera panel's meta line wrap the bearing after rounding to whole degrees, so a camera
+  facing 359.5° or more reads `HDG 0°` rather than `HDG 360°`.
 - **CCTV identified hardware:** a camera whose source or seed names a hardware `model` that
   resolves in `src/layers/cctv/modelSpecs.js` (vendored CC0 records from the CCTV Camera
   Database) gets the model's specs appended to the HUD meta line. Only fixed single-lens

src/layers/cctv/headingConfidence.js

@@ -44,7 +44,8 @@ export function isHeadingEstimated(camera) {
  * @returns {string}
  */
 export function headingHudToken(camera) {
-  const hdg = Math.round(Number(camera?.headingDeg) || 0);
+  // 359.5° and above rounds to north; modulo keeps it from printing 360°.
+  const hdg = Math.round(Number(camera?.headingDeg) || 0) % 360;
   return isHeadingEstimated(camera)
     ? t('HDG {value}° (ESTIMATED)', { value: hdg })
     : t('HDG {value}°', { value: hdg });

src/layers/cctv/headingConfidence.test.mjs

@@ -44,6 +44,15 @@ test('HUD token tags a synthetic bearing and rounds the degrees', () => {
   );
 });
 
+test('HUD token reads a bearing that rounds to north as 0°, not 360°', () => {
+  assert.equal(headingHudToken({ headingDeg: 359.4 }), 'HDG 359°');
+  assert.equal(headingHudToken({ headingDeg: 359.6 }), 'HDG 0°');
+  assert.equal(
+    headingHudToken({ headingDeg: 359.5, headingConfidence: 'low' }),
+    'HDG 0° (ESTIMATED)',
+  );
+});
+
 test('HUD token stays untagged for surveyed and calibrated bearings', () => {
   assert.equal(
     headingHudToken({ headingDeg: 67.5, headingConfidence: 'high' }),

src/ui/cctvControls.test.mjs

@@ -47,6 +47,30 @@ function fixture(t) {
   return { controls, requests };
 }
 
+test('the panel meta line reads a bearing that rounds to north as HDG 0°', (t) => {
+  const { controls } = fixture(t);
+  controls.actions.setPanelCollapsed = () => {};
+  controls._cctvMeta = element();
+  const meta = (headingDeg) => {
+    const camera = {
+      id: 'a',
+      city: 'Austin',
+      headingDeg,
+      fovDeg: 74,
+      rangeM: 700,
+    };
+    controls._renderCctvState({
+      enabled: true,
+      activeCameraId: camera.id,
+      activeCamera: camera,
+      cameras: [camera],
+    });
+    return controls._cctvMeta.textContent;
+  };
+  assert.match(meta(359.4), /· HDG 359° ·/);
+  assert.match(meta(359.6), /· HDG 0° ·/);
+});
+
 test('a late image completion cannot replace a newer camera preview', (t) => {
   const { controls, requests } = fixture(t);
   controls._queueCctvFrame('first.jpg', 'a', true);

src/ui/cctvPresentation.js

@@ -171,7 +171,7 @@ export function _renderCctvState(state) {
         '{city} · HDG {heading} · FOV {fov} · RANGE {range}m · {projection}{calBadge} · {provider}{status}',
         {
           city: activeCamera.city,
-          heading: `${Math.round(activeCamera.headingDeg)}°`,
+          heading: `${Math.round(activeCamera.headingDeg) % 360}°`,
           fov: `${Math.round(activeCamera.fovDeg)}°`,
           range: Math.round(activeCamera.rangeM),
           projection: projLabel,