Free-text market/event lookup by title, normalized context, or native id (v2)

Market/event lookup by free text — the MCP find_markets front door (UNIFIED_PLAN §7: "an agent that can't FIND a market can't use anything else"). Available to every tier — it reads the same uniformly- delayed catalog REST already serves (§131), never a live/paid-only surface.

Sources from db.search() -- the SAME matched_markets predicate markets() uses (active/review, complete_coverage, entity_confidence>=0.95), matched case-insensitively against team/league/sport/ market_type/slugs/native ids. Identity-only (no live price join): a lookup tool doesn't need prices, just enough to hand a market_id to /v2/markets or /v2/pairs/{id} for pricing detail — this keeps the endpoint fast and avoids duplicating the Centrifugo-history join machinery for a discovery surface.