chore(gitignore): ignore generated calib caches, cameo reports, and plots

These are regenerable per-run outputs that were polluting the worktree:
calibration caches (*.calib_cache.csv/png), cameo detection run outputs
(cameo_progress.txt, cameo_report.txt), and scene-gap analysis plots.

.gitignore

@@ -34,6 +34,16 @@ ort_cache/
 gallery.json
 gallery_*.json
 
+# Calibration cache (generated alongside a gallery, per-embedder)
+*.calib_cache.csv
+*.calib_cache.png
+
+# Cameo detection run outputs (generated by scripts/cameo_*.py)
+cameo_progress.txt
+cameo_report.txt
+
+# Analysis plot outputs (scene-gap histograms / KDEs, etc.)
+scene_gap_*.png
 
 # Per-frame debug images
 images/