MUL-6747: reduce runtime sweeper scan cost (#7628)

* perf(server): reduce runtime sweeper scan cost

Co-authored-by: multica-agent <github@multica.ai>

* fix(server): raise hourly runtime GC capacity

Co-authored-by: multica-agent <github@multica.ai>

* fix(server): address runtime sweeper review nits

Co-authored-by: multica-agent <github@multica.ai>

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Co-authored-by: Sol-Boy <sol-boy@multica-ai.local>
Co-authored-by: multica-agent <github@multica.ai>