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/presentation.js

@@ -1,5 +1,6 @@
 import { CCTV_AMBIENT_CARD_MAX } from '../../data/cctvLod.js';
 import { ACTIVE_FRAME_REFRESH_MS, IDLE_FRAME_REFRESH_MS } from './policy.js';
+import { headingHudToken, isHeadingEstimated } from './headingConfidence.js';
 
 export function createPresentation({
   state: layerState,
@@ -35,7 +36,9 @@ export function createPresentation({
     return [
       `${active.camera.city.toUpperCase()} CCTV`,
       `${active.camera.name.toUpperCase()}`,
-      `HDG ${Math.round(active.camera.headingDeg)}°`,
+      // A synthetic bearing (headingConfidence 'low', no human calibration)
+      // is tagged so a hashed guess never reads as a surveyed facing (#639).
+      headingHudToken(active.camera),
       `FOV ${Math.round(active.camera.fovDeg)}°`,
       `COVERAGE ${area.toFixed(2)}km²`,
       overlapCount > 0 ? `OVERLAP ${overlapCount} cams` : 'ISOLATED VIEW',
@@ -76,6 +79,11 @@ export function createPresentation({
       lat: camera.lat,
       lon: camera.lon,
       headingDeg: camera.headingDeg,
+      // Bearing provenance (#639): the pack's confidence flag plus the derived
+      // "is this a synthetic guess" bit (calibration-aware), so UI consumers
+      // never have to re-derive it.
+      headingConfidence: camera.headingConfidence || null,
+      headingEstimated: isHeadingEstimated(camera),
       pitchDeg: camera.pitchDeg,
       fovDeg: camera.fovDeg,
       rangeM: camera.rangeM,