docs: pools.trade event table — topic0 hashes inline + raw-event query example

[buddies2705]

Follow-up to #233, from reader feedback: the event-coverage table marked 13 events "❌ Raw" but the topic0 hashes needed to actually query them sat in a separate block further down — and there was no example at that spot showing how.

Changes

• topic0 column added to the event table — every row now carries its SignatureHash inline, including the decoded TokenCreated(address) (2e2b3f61…, with a "filter by Name" pointer).
• New section "Querying a raw event by topic0" immediately after the table: a copy-paste Events query (TokenDistributed) that works for any raw row by swapping the hash, plus the two practical notes — indexed args live in topics not Data, and CCA auction events should be filtered by topic0 alone since each Crowd Launch deploys its own contract (1,200+ live).
• The old hash block is reframed as "Full signatures for client-side decoding" (its remaining unique value: argument types for ABI-decoding LogHeader.Data).

Verification

• All 15 topic0s re-verified live on-chain (6 Aug): each fired within the prior 24h on robinhood_rt, emitters match the documented contract map (factory hash: single emitter, 18,885 events/24h).
• The new example query executed successfully against streaming.bitquery.io/graphql — returns seconds-fresh rows; LogHeader.Data decodes to the fixed 1B × 10¹⁸ launch supply as documented.

🤖 Generated with Claude Code