* improvement(tables): versioned CSV snapshot cache for table mounts + parallel multipart uploader
* chore(db): drop colliding 0239 migration (renumber pending)
* chore(db): renumber rows_version migration to 0240 (off staging's 0239)
* improvement(tables): mount snapshots by presigned URL so the sandbox fetches directly (raise cap to 500MB)
* fix(tables): allow url sandbox entries in the function-execute contract; key snapshot by column shape so schema edits invalidate it
* chore(e2b): log sandbox inputs split by url-fetch vs inline write
* improvement(tables): order export + snapshot rows by order_key so the CSV matches the grid under fractional ordering