refactor(emit): drop aggregation_id from OTAP YAML + Telegraf TOML wire

[zzylol]

Summary

Mirrors the PR-5 wire-cleanup pattern (#244 / #246 / #250), now for the edge-side runtime emitters. The patched asap-otel processors (any runtime: OTel collector / OTAP / Telegraf) don't consume the controller-allocated aggregation_id string — sid identity is content-addressed at the backend via (metric_name, attrs_fingerprint, agg_kind_canonical), and policy_fp content-matches via (metric, sketch_kind, config, group_by_keys). The controller-allocated string is dead weight on the wire.

The OTel-collector YAML emitter (emit_edge_yaml) was already clean — an existing test asserts the agent YAML does NOT contain aggregation_id:. This PR catches the two remaining edge-runtime emitters:

• emit/otap.rs::build_asap_sketches_config — drops the aggregation_id map entry from the OTAP DAG YAML.
• emit/telegraf.rs::emit_processors_allsketches — drops the aggregation_id = ”…” TOML line.

EdgeSketchProcessor.aggregation_id stays on the struct as internal emitter plumbing for cross-stage references during the DAG walk (SketchAgg → BackendAggregation → BackendReadout); it just doesn't reach the wire from any runtime emitter anymore.

Verified asap-otel doesn't consume the field

grep -rln "aggregation_id\|AggregationId" /mydata/ASAPCollector/opentelemetry-collector-contrib/processor/{ddsketch,hll,kll,countsketch,countminsketch}processor/ → zero matches. The patched processors don't read the field on any runtime; the agent silently ignores it on the OTel-collector path too.

Test plan

• cargo test --lib -p control_plane: 690 passed; 0 failed
• cargo test --tests --bins -p control_plane: 27 passed; 0 failed
• No tests asserted the field was present in OTAP / Telegraf output, so no test-flips needed.

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