feat(memory): make local record capacity configurable

[patrick-ogrady]

Summary

• add a positive memory.max_records setting for local memory while preserving the 512-record default
• derive local aggregate-content capacity from the record count and fixed 1 KiB per-record limit
• apply the configured count to runtime storage and push/pull snapshots while leaving remote capacity service-owned

[patrick-ogrady]

given records already have a capped size, I think you could just limit by max_records.

[codspeed-hq]

Merging this PR will not alter performance

✅ 18 untouched benchmarks
⏩ 31 skipped benchmarks¹

---

_{Comparing memory-capacity (1357f73) with main (ee5b1ca)}

Footnotes

1. 31 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩