[Feature]: Memory control for creating and optimizing indexes

[iaojnh]

Problem / Motivation

Currently, Zvec does not impose memory limitations during index creation and optimization. With large indexes, this consumes a significant amount of system memory for related operations. We aim to successfully create and optimize indexes even with limited memory.

Proposed Solution

Add `memory_limit_mb` args to collection schema or global configuration

Alternatives Considered

No response

Affected Area

No response