fix(cctv): surface heading confidence — estimated bearings are now visible

Every pack sets headingConfidence on each camera, but nothing consumed it:
a bearing synthesized by fallbackHeadingFromId (a hash of the id string,
no geographic input) rendered exactly like a surveyed one — 2,827 of 3,997
cameras in a default catalog. Fixes #639.

Two consumers, plus a passthrough:

- HUD: the heading token is tagged when the bearing is synthetic —
  `HDG 194° (ESTIMATED)` — so a hash never reads as a measured facing.
- Wireframe: a low-confidence camera draws its coverage frustum with dashed
  polylines instead of solid ones. Colors, widths, and the active/idle
  emphasis are unchanged; the dash is the only signal.
- Public camera state gains `headingConfidence` (the raw pack flag) and
  `headingEstimated` (the derived bit) so UI consumers never re-derive it.

A human-vouched pose always wins over the pack flag: a manually saved
calibration (calSource:'manual') or a curated catalog entry
(poseSource:'curated') is never presented as estimated, mirroring the CAL
badge states in calibration.js.

- src/layers/cctv/headingConfidence.js: pure helpers (isHeadingEstimated,
  headingHudToken)
- src/layers/cctv/headingConfidence.test.mjs: confidence normalization,
  calibration/curation overrides, HUD token formatting
- src/layers/cctv/presentation.js: HUD token + public-state passthrough
- src/layers/cctv/rendering.js: dashed materials for estimated bearings

src/layers/cctv/headingConfidence.js

@@ -0,0 +1,47 @@
+/**
+ * @module headingConfidence
+ *
+ * Consumers for the catalog's per-camera `headingConfidence` flag (#639).
+ *
+ * Packs whose feed publishes no facing get a synthetic bearing from
+ * `fallbackHeadingFromId` — a hash of the id string, with no geographic
+ * input — and are marked `headingConfidence: 'low'`. Until now nothing read
+ * the flag, so a guessed bearing rendered exactly like a surveyed one. These
+ * helpers make the guess visible: the HUD heading token gains an
+ * `(ESTIMATED)` tag and the coverage wireframe draws dashed instead of solid.
+ *
+ * A human-vouched pose always wins over the pack flag: a manually saved
+ * calibration (`calSource:'manual'`) or a hand-authored catalog entry
+ * (`poseSource:'curated'`) is never presented as estimated, mirroring the
+ * CAL badge states in calibration.js.
+ */
+
+/**
+ * Whether a camera's bearing is a synthetic guess that should present as
+ * provisional.
+ * @param {{headingConfidence?: string|null, calSource?: string|null,
+ *   poseSource?: string|null}} camera - Catalog camera (or public state).
+ * @returns {boolean}
+ */
+export function isHeadingEstimated(camera) {
+  if (!camera) return false;
+  if (camera.calSource === 'manual') return false;
+  if (camera.poseSource === 'curated') return false;
+  return (
+    String(camera.headingConfidence || '')
+      .trim()
+      .toLowerCase() === 'low'
+  );
+}
+
+/**
+ * HUD heading token: `HDG 194°`, tagged `(ESTIMATED)` when the bearing is
+ * synthetic — so a hash can never read as a surveyed facing.
+ * @param {{headingDeg?: number, headingConfidence?: string|null,
+ *   calSource?: string|null, poseSource?: string|null}} camera
+ * @returns {string}
+ */
+export function headingHudToken(camera) {
+  const hdg = Math.round(Number(camera?.headingDeg) || 0);
+  return `HDG ${hdg}°${isHeadingEstimated(camera) ? ' (ESTIMATED)' : ''}`;
+}