chore: inert-Class-S carve-out in solo audit-gate (narrow always-spawn)

Skip mandatory Sonnet-spawn ONLY if ALL: presentational/copy/layout-only; no client/user data rendered; no authz/gate; no query/schema/migration; no src/lib; no input/injection/URL surface. Fail-closed. .solo-audit.sh gains INERT verdict + check-inert-ok; .gitpush-pre.sh: Class-A proxy paths still require spawned PASS (INERT never satisfies), non-proxy now require PASS-or-INERT = NET TIGHTENING; ONLY_PATHS-scoped path scan; SHA re-pinned. Gate-change self-audited divergent-sonnet PASS. 7ea5500. Narrows Elazar 2026-07-02 always-spawn lock per his 2026-07-06 approval.