feat(query): bind SID reads to active materializations

[zzylol]

Summary

• derive the allowed materialization set from active warm BackendPlan routes
• carry that set in each immutable query execution context
• exclude stale or unrelated SIDs even when metric, grouping and family match
• retain explicit legacy behavior only when no BackendPlan exists

Validation

• cargo test -p data_plane query_engines::asap_query_engine --lib (89 passed before the focused regression addition)
• cargo test -p data_plane backend_plan_materialization_filter_excludes_stale_sid --lib
• git diff --check

Stack

Depends on #464.