Synced skills namespaced to avoid colliding with local skill or command names

What

• Skills that come from account sync (claude.ai) can now be referenced and stored under a namespaced key like anthropic-skills:<name>. A helper strips this prefix when looking the skill up, and a synced skill whose bare (short) name collides with a local or plugin command is no longer simply dropped — it stays usable under its namespaced name.
• When Claude Code builds its /context inventory of tools and skills, a synced skill's bare/unqualified name is no longer treated as claiming that name slot, so it can't silently take over an unqualified name that a locally defined skill or command also uses.
• Name matching for tools and skills now handles synced skills as a special case: instead of using the generic name-suffix matching heuristic, it matches against the skill's own declared aliases.

Why

Before this, a skill synced from your claude.ai account could quietly take over a name also used by a skill or command defined locally, either shadowing it or getting dropped outright. Namespacing synced skills and changing how their names are matched means both the synced version and a same-named local skill or command can coexist and be referenced correctly.