Follow-up on the salvaged commit: the xurl skill loads even when x_search
isn't registered (check_fn-gated on xAI credentials), so per the
cross-toolset reference rule the skill must not name it. Replaced the
skill's x_search routing block and workflow step with skill-native
wording (raw engageable posts, authenticated context, write-evidence
rule). The cross-surface comparison stays on surfaces where both are
known to exist: x-search feature docs, toolset description, tools-config
setup note, and the x_search tool schema (kept generic, no tool names).
Rewrote the routing tests to pin the placement contract, including that
the skill never names credential-gated surfaces.
6441b05888