Tighten datasheet model matching and keep given fields of view

Codec, product and resolution words never identify a model; generation suffixes such as Mk II no longer fall back to the base model; a mismatched manufacturer never matches, and brand-only numeric names need the brand. The datasheet FOV only fills when the source and seed give none and the pose is not curated, and DATASHEET is shown only while no calibration offset applies. Adds the CC0 extract to DATA_SOURCES.

docs/CURRENT-STATE.md

@@ -4185,7 +4185,8 @@ silently demoting every later lookup for the session.
 - **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
-  hardware replaces the estimated FOV, shown as `FOV n° (DATASHEET)`. PTZ, varifocal and
+  hardware fills the FOV, and only when the source or seed states none and the pose is not
+  curated, shown as `FOV n° (DATASHEET)` until a manual calibration moves it. PTZ, varifocal and
   multi-sensor datasheets publish a capability range, not the lens's current zoom, so those
   cameras keep their estimate and show `SPEC FOV min–max° (CAPABILITY)` beside it. Public
   camera state carries `fovSource`, `specFovMinDeg`, `specFovMaxDeg` and `spec` (#452).