Authority snapshot bounds are incompatible with od-base (14 tests deselected in heavy) #29

tests/challenge/test_authority_snapshot_v2.py (14 tests) cannot run on od-base, so PR #26 deselects them by name in heavy.

• The 48-trial fixture writes ~190 GB on od-base.
• The exported od-base start_state is 1.48 GB, above scripts/network_authority_snapshot.py MAX_FILE (16 MiB) and MAX_BYTES (1 GiB); export fails with "snapshot file size/type" after ~65 min.
• Lifting the bounds inside the test was rejected: it would stop proving the real bounds and does not fit the runner disk.

Decision needed (founder chose option A on 2026-10-21 for the fixtures, with this as a documented residue): either a snapshot format for od-base (chunked or by-reference state) with its own bounds, or a reduced-trial fixture that keeps the real bounds. Until then these 14 ids are not exercised in CI.