Function classify_skill_collision 

pub fn classify_skill_collision(
    slug: &str,
    global_slugs: &HashSet<String>,
    in_bundle_dupes: &HashSet<String>,
) -> &'static str

"none" / "name_conflict" / "duplicate_in_bundle" — Phase 3 spec §3.1’s two-pass skill collision classification. global_slugs is whatever the caller already fetched from skill.catalog.list’s underlying skill_list_global() (Store access lives in the RPC handler, not here — this stays a pure function so it’s testable with a seeded fake global-skill list, per the spec’s own §6 testing notes). Pass 1 (global catalog) takes priority over pass 2 (intra-bundle duplicate) when both apply, matching §3.1’s stated precedence.