feat: add batch MCAP export tooling for ZED segments

Add a Python batch wrapper around zed_svo_to_mcap for multi-camera
segment exports. The new script supports dataset discovery, repeated
segment-dir inputs, CSV-driven ordering, skip/probe/report flows, dry-run,
and CUDA environment passthrough so kindergarten-style datasets can be
converted into one bundled MCAP per segment.

Extend zed_svo_to_mcap so bundled multi-camera mode accepts --end-frame
with synced-group semantics. In this mode the value is interpreted as the
last emitted synced frame-group index from the common synced start, while
--start-frame remains unsupported.

Vendor a minimal pose-config TOML and a sample segments CSV into this repo
so the MCAP workflow is self-contained. Update the README to document the
batch MCAP flow, use portable placeholders instead of machine-specific
absolute paths, and describe the expected dataset layout explicitly.

config/svo2_segments_sorted.sample.csv

@@ -0,0 +1,7 @@
+timestamp,activity,group_path,segment_dir,camera,relative_path
+2026-03-18T11-23-22,jump,jump/external/recording,jump/external/recording/2026-03-18T11-23-22,zed1,jump/external/recording/2026-03-18T11-23-22/2026-03-18T11-23-22_zed1.svo2
+2026-03-18T11-23-22,jump,jump/external/recording,jump/external/recording/2026-03-18T11-23-22,zed2,jump/external/recording/2026-03-18T11-23-22/2026-03-18T11-23-22_zed2.svo2
+2026-03-18T11-23-22,jump,jump/external/recording,jump/external/recording/2026-03-18T11-23-22,zed3,jump/external/recording/2026-03-18T11-23-22/2026-03-18T11-23-22_zed3.svo2
+2026-03-18T11-23-22,jump,jump/external/recording,jump/external/recording/2026-03-18T11-23-22,zed4,jump/external/recording/2026-03-18T11-23-22/2026-03-18T11-23-22_zed4.svo2
+2026-03-18T11-26-23,jump,jump/experiment/1,jump/experiment/1/2026-03-18T11-26-23,zed1,jump/experiment/1/2026-03-18T11-26-23/2026-03-18T11-26-23_zed1.svo2
+2026-03-18T11-26-23,jump,jump/experiment/1,jump/experiment/1/2026-03-18T11-26-23,zed2,jump/experiment/1/2026-03-18T11-26-23/2026-03-18T11-26-23_zed2.svo2