SQL: capability-matching rejects every grouped COUNT/SUM aggregation the planner actually builds #529

Scope: streaming_engine=precompute, SQL.

For CountMinSketch, the planner routes GROUP BY columns into aggregated_labels and leaves grouping_labels empty (asap-planner-rs/src/planner/labels.rs:15-21, set_subpopulation_labels).

The engine's capability-matching requirement builder always populates grouping_labels from the literal SQL GROUP BY columns (asap-query-engine/src/engines/simple_engine/sql.rs:318-322, build_query_requirements_sql), and labels_compatible (asap_types/src/capability_matching.rs:82-84) requires an exact match between config.grouping_labels and requirements.grouping_labels.

Result: a real planner-shaped CountMinSketch config (grouping_labels=[], aggregated_labels=[...]) never satisfies a capability-matching request for the same query, even though it's exactly the right aggregation.

Repro: built a SimpleEngine with a planner-shaped CountMinSketch(sub_type="count") config and no query_configs; SELECT COUNT(cpu_usage) FROM t WHERE time BETWEEN ... GROUP BY datacenter → None. Confirmed at the find_compatible_aggregation unit level too.

Related: #386 (same label-routing mismatch, previously fixed only for spatial MinMax; this shows it still exists for CountMinSketch).