Changelog

• d780baf chore: bump version to v3.20.4 [skip-release] [skip ci]
• 9c955cd feat(agent): add ground-truth data-accuracy eval loop
• 9718984 feat(agent): teach the engine to compute — truncation guardrails, current_date, data_aggregation skill
• 82fa29d feat(agent,serv): teach order_by-on-aggregate now that the compiler ranks correctly
• 47f06ea feat(console): redesign web UI and add homepage showcase
• 3f56ab7 feat: migrate MCP to official SDK
• 27ef426 fix(clickhouse): preserve grouped aggregate dimensions
• 2c8bb33 fix(dialects): preserve grouped aggregate ordering
• 4c50821 fix(qcode): authorize analytics window columns
• 737fae2 fix(qcode): enforce related order function policy
• 5ab4ef3 fix(qcode): enforce role authorization on order_by and distinct columns
• b2f5a6a fix(qcode): enforce where column authorization
• 491c84c fix(qcode): keep GROUP BY intact when ordering by an aggregate field
• d1298c7 fix(scripts): never kill a port this eval run did not boot
• 60a26bc fix(scripts): one ledger entry per eval run
• b5b0c28 fix(scripts): resolve eval paths against the caller and validate before booting
• c6f28cb fix(scripts): stop the port sweep from killing the eval runner itself
• 0fd47bc perf(agent): merge write-side watch skills
• 85673a0 test(qcode): pin order_by/field authorization parity and cursor PK exemption