Add duplicate-view capture diagnostics

CHANGELOG.md

@@ -53,6 +53,8 @@
   positive scales, and quaternion normalization.
 - Capture manifests now reject unsupported coordinate-convention declarations,
   making COLMAP world-to-camera assumptions machine-checkable.
+- Capture readiness reports now flag exact and near-duplicate view pairs in
+  addition to source-media quality warnings.
 - Added `EXPERIMENT_TEMPLATE.md` for repeatable dataset, calibration, metric,
   failure, and claim-boundary records.
 - Added regression coverage for rejecting capture-image path traversal.