docs: query comments say what each query selects and why, not how it came to be (#6277)

Rewrites the internal/db/queries comments to rule 32 and regenerates
dbq, whose doc comments and embedded SQL carry them. The bugs behind the
tiered mixes, the md5 order seed, the score bands and the round-robin
arms are restated as the constraint each one enforces; counts from one
library and stale cross-references are gone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/db/queries/audit_log.sql

@@ -15,7 +15,7 @@ SELECT count(*)::bigint FROM audit_log
 
 -- name: ListAuditLogByActions :many
 -- One page of the given actions, newest first: the duplicates report's
--- "resolved automatically" activity (M498) reads the resolver's merges from
+-- "resolved automatically" activity reads the resolver's merges from
 -- here.
 SELECT * FROM audit_log
  WHERE action = ANY(sqlc.arg(actions)::text[])