refactor(h3d-carve-9): extract W-section (camera lerp) → src/camera.js

effectiveVfov + camUpdate (~192 lines) extracted from the screen.js IIFE
into a createCamera() ES-module factory in plugins/highway_3d/src/camera.js.
screen.js imports and destructures the return { effectiveVfov, camUpdate }.

DI surface (48 params): 22 plain constants, 11 getters, 5 getter+setter pairs,
5 fn-refs (DI-renamed: _freeCamFor→freeCamFor, _aspectPaneKey→aspectPaneKey,
_resolveTuneFor→resolveTuneFor, _aspectRegisterPane→aspectRegisterPane).
Peer ES imports at module level: computeBPM (geometry.js), _ssActive (utils.js).
Per-call write-backs: setCurX, setCurDist, setCurLookY, setTgtLookY,
setFretRowFitBoost (all write-backs confirmed by setter class-killer tests).

Test retargeting (54 tests across 4 files):
- highway_3d_wide_fov.test.js:   6 tests → cameraSrc; 4 regexes updated for
  DI-renamed fn refs (resolveTuneFor, aspectRegisterPane, aspectPaneKey/getPaneUid)
- highway_3d_camera_framing.test.js: 5 tests → cameraSrc; getTgtDist() regex fix
- highway_3d_camera_bootstrap.test.js: extractFn retargeted to cameraSrc;
  getTgtX() ordering-check fix; 2 new setter class-killers added (setCurX,
  setFretRowFitBoost)
- highway_3d_lefty.test.js: shoulder-offset test → cameraSrc + getLeftyCached()
- highway_3d_panel_controls.test.js: createCamera stub added

Bite proofs:
- Gut effectiveVfov in camera.js → wide_fov not ok 4 (RED) ✓
- Gut camUpdate body (H_NEAR lerp) → framing not ok 3 (RED) ✓
- Gut camUpdate body (curX+=) → bootstrap not ok 11 (RED) ✓
- Sever setCurX → bootstrap not ok 12 (RED) ✓
- Sever setFretRowFitBoost → bootstrap not ok 13 (RED) ✓

Suite: 1271/1273 pass; 2 pre-existing failures unchanged from cut-8 baseline
(#46 analyser fallback, #591 nut-labels — both in flight before cut 9).

plugin.json: 3.44.0 → 3.45.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014uZ169yfoFYArXz962g7KW

tests/js/highway_3d_panel_controls.test.js

@@ -130,6 +130,11 @@ function loadHighway3dStatics() {
             _applyBloom() {},
             _bloomEnsure() { return null; },
         }),
+        // h3d-carve-9: W-section (camera lerp) moved to src/camera.js.
+        createCamera: () => ({
+            effectiveVfov() { return 70; },
+            camUpdate() {},
+        }),
     };
     vm.createContext(sandbox);
     vm.runInContext(instrumented, sandbox, { filename: SCREEN_JS });