Add a thin async ESI client (httpx, descriptive User-Agent, uniform errors,
mockable transport) plus name<->id resolution. New read-only tools:
- universe: resolve_names, get_item, get_system, get_station, get_region, get_route
- market: list_hubs, get_market_price, get_market_orders, compare_hubs
Trade-hub IDs (Jita/Amarr/Dodixie/Rens/Hek) are hardcoded constants. Market
aggregation (best buy/sell, spread, order book) lives in pure helpers. 30 unit
tests with mocked ESI; coverage 99%. SDE bulk-load deferred to a later phase.
Closes#2
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
