Prove the new tools are reachable, not just correct

The post-wiring smoke ran sealed (MIKE_DISABLE_RESEARCH_TOOLS=1), so it
exercised the SLA loop but never touched caselaw_note_up,
library_compare_versions, or grep-mode find. Their unit tests prove the
executors work; nothing proved the dispatcher reaches them or that the
research gate puts them on the right side of the line.

Four checks, no model needed: the always-on document tools are advertised;
library_find exposes regex/case_insensitive and library_read exposes
offset/max_chars as real parameters; the citator disappears under the
research switch while document tools survive it; and dispatching
caselaw_note_up / library_compare_versions returns each executor's own
typed refusal rather than an unknown-tool reply.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018bhP89cYSdEEjHNPnxacns