fix: correct fabric entity taxonomy and Smithville coverage summary

[downwithbgp]

Summary

Freeze-exception correctness repair (internal project-owner walkthrough; zero external evaluation sessions; pilot registry remains zero).

MAN LAN entity taxonomy correction

• Ixia misclassification corrected: Ixia is network test/measurement equipment — not an autonomous system, not a BGP peer, not a participant network, and not a reviewed fabric attachment. It is removed from the fabric diagram, attachment table, and attachment count, and rendered only as test-equipment context (no ASN, no attachment edge, no BGP edge).
• Complete entity audit (NORDUnet, ESnet, GÉANT, CANARIE, TWAREN, SINET, Ixia, NEAAR, OMAN, WIX interconnect) against tracked reviewed evidence (target-research.json, PILOT-SELECTION.md, AAR extraction).
• Bounded entity taxonomy in the reviewed interconnection context: AttachedNetwork / TestEquipment / InterconnectContext / OperationalService / UnresolvedMention, with a dated classification-review record (prior 10 attachments → corrected 5).
• Corrected attachment count: 10 → 5 reviewed attached networks (NORDUnet AS2603, ESnet AS293, GÉANT AS21320, CANARIE AS6509, SINET AS2907). WIX interconnect = interconnect context; NEAAR = service reference; Ixia = test equipment; TWAREN (AS7539 retained as identity detail) and OMAN = unresolved mentions.
• Historical ASN roles reviewed (GÉANT attachment identity AS21320 vs path-observed AS20965 documented, not conflated).

Smithville event-page summary and provenance

• Observation coverage summary (collector, collector site, source family, target visibility, reviewed-relationship visibility, qualification) derived from canonical preflight evidence: 5 collectors checked, 13 AS11550 prefixes visible at IPv4 collectors, 0 of 923 AS11550 routes traverse AS19782, 0 direct AS19782 observer sessions, 0 on the IPv6-only collector; why this is Insufficient qualifying visibility and why no UPDATE archives were acquired.
• Snapshot/cutoff provenance: demo import now prefers the latest reviewed immutable snapshot (INC0301970.source.json, the 2026-08-04T00:01:37Z exact source refresh) over the older 07-31 fixture, via a generic case-study snapshot rule with a reviewed sidecar meta. Source snapshot fetch time, source lifecycle at that snapshot, analysis cutoff, and cutoff provenance are distinct fields.
• Status labels: "Analysis status" (Complete) and "Source lifecycle" (Open) are distinct; Complete never implies event closure.
• Assessment leads with the operator-readable explanation (target visibility vs relationship visibility); exact machine classifications preserved as secondary detail.

Evidence

• Canonical BGP artifacts changed: none; canonical BGP hashes changed: none; immutable source snapshots mutated: none (tracked snapshot SHA-256 verified unchanged).
• Reviewed interpretation changed: case-studies/manlan-2019/case-study.json (entity taxonomy correction with review record), new observation-coverage.json, new snapshot meta sidecar, docs, facilitator truths, regenerated answer key.
• No analysis rerun; no source contacted; no acquisition.