feat: expose virtual-forward flag in event CTEs

[o-az]

Summary

• Expose logs.is_virtual_forward on event CTEs for PostgreSQL and ClickHouse
• Allow raw predicate pushdown for is_virtual_forward filters
• Keep /status fast/reliable by removing synchronous block gap detection from the HTTP request path
• Update query skill docs, changelog entries, tests, and CTE snapshots

Why

TIP-1022 virtual-address deposits emit both sender -> virtual and virtual -> master Transfer logs. Event CTE consumers need is_virtual_forward to avoid surfacing or counting the forwarding hop as a normal transfer.

Production also showed /status returning DB errors because the endpoint ran an expensive gap-detection window scan over blocks on every request. Exact gap discovery now stays in the background gap-fill path instead of the API status path.

Test

• cargo test query::parser::tests
• cargo check
• cargo test --test status_test --no-run

Note: cargo emits the existing unused synced_num warning in src/cli/status.rs.