Close the deferred Vault item 4: a read-only endpoint proving a selected
vault entry is recallable by CORE's actual exact CGA machinery, surfaced
in the entry inspector.
Backend (read-only, cold-persisted only):
- GET /vault/entries/{index}/recall rehydrates the persisted VaultStore
(VaultStore.from_dict — bit-exact versors, no reprojection) and runs the
real VaultStore.recall using the entry's own stored versor as the query.
Exact cga_inner scan — never ANN / cosine / approximate.
- recall's +inf exact-self-match sentinel never crosses the boundary: the
genuine finite cga_inner is reported plus an exact_self_match flag. The
raw versor never leaves the engine — only content-addressed digests.
- Trust boundary: caller-controlled index -> 404 (out of range / non-int);
absent persisted snapshot -> 501. The file is never written; the live
runtime is never touched; recall is deterministic over persisted bytes.
Frontend:
- "Exact CGA Recall" inspector panel, collapsed by default so the read is
opt-in (the query hook only mounts on expand). Copy says "exact CGA
recall" / cga_inner — never similarity / relevance / score / ANN /
cosine. Honestly surfaces that a byte-identical self-match is promoted
ahead of metric ranking (CGA null-vector self inner-product ~0).
INV-24: register workbench/readers.py in VAULT_RECALL_SITES as
EVIDENCE_TELEMETRY (operator inspection evidence, not claim-shaping), and
tighten the recall-site detector to recognise VaultStore.from_dict factory
bindings so the obligation is real rather than silently bypassed.
Tests: backend 501/404/self-recall/determinism/no-mutation/JSON-safety +
API status codes; frontend collapsed-doctrine + expanded self-recall
evidence. Full workbench suite (192) + architectural invariants (61) +
vault-touching vitest (70) all green.