Reuse attachment thread segment sanitizer in projection pipeline

- export and reuse `toSafeThreadAttachmentSegment` from `attachmentStore`
- align projection attachment path logic with store-safe thread IDs
- update projection pipeline tests to cover thread IDs with spaces
a56418f8bcJulius Marminge committed on 3/2/2026, 4:06:21 AM· committed by Julius Marmingeparent596e159
3 files changedLine totals unavailable