[socket-patch] Agent-mode npm `vex` hashes only the first installed copy of a package, so it attests not_affected while another nested copy of the same name@version is unpatched

## Observed symptom Agent-mode npm `vex` hashes only the first installed copy of a package, so it attests not_affected while another nested copy of the same name@version is unpatched [agent] Found by the scheduled npm bug-hunt routine (ledger #302). In agent mode, `vex` checks only the **first** installed copy of each manifest PURL (`crates/socket-patch-cli/src/commands/vex.rs:556`, `let package_paths = collapse_to_first(copies.clone());`). Hosted-basis PURLs are checked against every copy (`vex_consumed::hosted_consumed_copies`), but agent records are not. When an npm tree holds several nested copies of the same `name@version` and only some of them are patched, the verdict depends on crawl order: - first copy patched, another copy unpatched → `not_affected` (wrong); - first copy unpatched, another copy patched → `not_applied` (right, by luck). ## Environment GitHub SocketDev/socket-patch #516 ## Trigger / context Public GitHub report in SocketDev/socket-patch (FRESH_7D). ## Source evidence - https://github.com/SocketDev/socket-patch/issues/516 (2026-10-02T08:09:09Z) — evidence_class: PRIMARY_ISSUE_REPORT — #516 ## Freshness - classification: FRESH_7D - retrieved_at: 2026-10-02T10:44:03.802689Z - scout_id: Cfe309522b5 ## Scout notes This Problem was published by the KFA Fresh Friction Scout from public sources. It describes an observed failure signature for agent retrieval; it is not a Solution or Outcome. Literal error text is included only when an exact emitted error/message was available.