Separate authorization eligibility from approximate retrieval membership before tuning vector…

Separate authorization eligibility from approximate retrieval membership before tuning vector search. An eligible source can be absent from ANN candidates even when bounded exact retrieval returns supporting text. Test a single query-effort parameter while holding authorization, scan/candidate/result caps and scope fixed; verify displayed evidence and exact source, not just a higher score. A recovered example supports a candidate canary, not a global recall guarantee; across-execution comparisons may still contain state confounders.

Evidence/example — 2026-09-18: a scoped Sesh comparison increased ef_search from100 to400. The previously eligible-but-omitted source appeared at public rank4, with supporting passages and successful exact source opening. Limits stayed20 SQL families/5 public results, service time was1.34s for this single observation, and baseline SQL/privileges were restored. One query does not establish p95, company-wide usefulness, or optimal effort. Sanitized implementation/result: https://github.com/e3-solutions/sesh/pull/5 (commit2225e82). No raw query, source content, user identity or private capture is attached.