v1.108.167 — cue-anchored delivery ledger: measure what we hand over twice

Cue-anchored delivery ledger: measure what we hand over twice

jCodeMunch counted byte-identical repeat calls (yield.repeated_identical_calls)
and consumed the count nowhere. Worse, that counter is blind to the shape that
actually costs: the same symbol re-delivered under a different query.

search_symbols("auth handler") and get_ranked_context("who validates the token") can return the same three bodies at full byte cost, with two different
argument hashes. One set of bytes, paid for twice, invisible to every meter.

P0 — the measurement, and the gate

A session-scoped delivery ledger now reports redelivered_symbols,
redelivery_rate and redelivered_tokens_est in the yield block of
get_session_stats.

The measurement is the deliverable. A binding, pre-registered decision rule
says suppression only ships if the measured rate clears 10% — a threshold set
before the number exists, and honored after. Same discipline as the v1.108.149
cache-stability work, where the pre-registered kill threshold told us to hold a
feature and we published the hold.

P1 — annotation, not suppression

A response carrying symbols the session already received gets an advisory
_meta.already_delivered = {count, symbols}.

No response body changed. Nothing is suppressed. You are told you are
holding the bytes again, never quietly denied them. Telling an agent it already
has something may fix most of this on its own, and it costs nothing to find that
out before building a governor.

Notes

• note_served is deliberately untouched. Its record is what finalize_handoff
  attests evidence_refs against, so the ledger sits parallel to it rather than
  silently changing what a handoff can cite.
• Only full-source deliveries are priced. Re-showing a signature row is reported
  but never charged; a symbol first seen as a search row and later fetched in
  full is new bytes, not a redelivery.
• Editing a file evicts its ledger entries, so stale bytes are never announced
  as already-delivered.
• Byte-identical for existing callers. No new tool, no schema, tool-count or
  INDEX_VERSION change. Ledger is in-memory, process-lifetime, never on disk.

Origin: Token Cost Radar 2026-07-24 research watch (arXiv 2607.20972,
cue-anchored working memory). Clean-room. The paper's intra-session reread
figure is theirs over their harness and is deliberately not claimed here — we
publish our own number or none.