Status: PASS / FAIL_CLOSED / BROKER_CUSTODY_PENDING / PRODUCTION_NO_GO

Implementation: R2_GITHUB_OBSERVER_V1_6_DURABLE_REOBSERVATION_JOURNAL.

V1.6 fixes an auditability defect: the historical v1 observer ledger projected only the first receipt for a given PR/head because of a unique (pr_number, head_sha) index. A later fresh signed observation of the same PR/head could therefore be returned to a caller without being durably represented as a reconstructable signed receipt in that legacy projection.

V1.6 adds authoritative journal observer_receipts_v2 with a non-unique PR/head/time index. Every fresh signed receipt is stored in full, including broker implementation, invocation mode, signature metadata and complete receipt JSON. The old v1 projection is retained only for first-observation compatibility.

New root-only evidence surfaces:

• GET /v2/ledger
• GET /v2/receipt/:sha

Database re-observation test evaluation 01a04c6a-4412-7312-9111-c55b1247e345 — PASS: two receipts with the same PR/head and different invocation modes were simultaneously journaled, the index was confirmed non-unique, and synthetic test rows were removed with zero residue.

Branch selftest evaluation 01a04c6c-917c-730f-a653-a3e1b1d3dd73 — PASS. V2 ledger is root-only, live observation remains fail-closed at broker custody, fixture signature verifies, tamper fails and audit chain passes.

Static source audit: 18/18 PASS.

Broker trust root advances to R2_GITHUB_APP_CUSTODY_BROKER_V1_3_OBSERVER_JOURNAL_PINNED. Native enforcement remains mandatory and production_go=false.