Sync schemas/tool-groups.json to pack-spec 4.19.0 (lens group added)

[piersdd]

Filed from the vault#17 exploration (2026-08-12); AI-generated.

pack-spec v4.19.0 (stallari-pack-spec#16) added the lens tool group to vocabularies/tool-groups.yaml. This repo's schemas/tool-groups.json still carries the 11-group copy (no lens) and needs its sync run against 4.19.0.

Context: stallari-vault#17 — the vault enum ↔ spec vocabulary parity fix. Additive only; no schema consumer validates against the group list, so this is a staleness cleanup, not a break.

Acceptance criteria

• schemas/tool-groups.json matches pack-spec dist/json/tool-groups.json at v4.19.0 (12 groups incl. lens)

[piersdd]

This was generated by AI during triage.

Agent Brief

Category: enhancement · Summary: sync schemas/tool-groups.json to pack-spec 4.19.0 (adds lens).
Premise verified: plugins schemas/tool-groups.json has 11 groups, no lens; pack-spec dist/json/tool-groups.json has 12 (vocabularies/tool-groups.yaml:31). No consumer validates against the group list. 1–2 files (schemas/tool-groups.json, Makefile sync target). Sibling stallari-vault already re-synced (7930a40).
CONV-40 rule 2. Operator ruled ready-for-agent + svd:go 2026-09-04.