store.sh enqueue becomes the SOLE allocator of observed_seq: under an exclusive
enqueue lock it reads its own cursor, sets next=observed_seq+1, writes the
pending record + observed.set + the cursor as ONE transaction (cursor committed
IFF the durable write succeeds), and prints the allocated seq. The detector's
private observed_seq_counter and its --seq hand-off are deleted; the reconciler
enumerates via the same store allocator and its dual-allocator fail-closed guard
is retired. This dissolves the three defects rooted in the private-counter seam:
burn-before-enqueue, W5 co-feed aliasing, and the migration-restart silent-swallow.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0158NZqN2n2ymKFeJAZ4GUCb
