`rust/src/sliding_sync/room.rs` holds the parts of `get_room_sync_data`
that make no reads:
- the timeline bounds (`from_bound`, `initial`, the expanded timeline)
- `num_live`
- the stripped state of an invite or knock
- the string fields of the name, avatar and member events, and the
hero assembly
- `_get_bump_stamp` split around its two reads, plus the
`always_return_bump_stamp` rule and the clamp to zero
- the room config the connection records afterwards
Three of these move, unchanged, out of `get_room_sync_data` into Python
helpers, so the tests compare against the real code: `_timeline_bounds`,
`_stripped_state` and `_room_config_to_persist`. `_get_bump_stamp` is
tested as it is, with a stand-in store.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L51DoxB8VnH8UjXJFDgpNG
