Hermes nmem_search should expose minimum-importance filtering

[ferstar]

Summary

The Hermes native Nowledge Mem provider exposes nmem_search with query, limit, label filtering, and search mode, but it does not expose the nmem CLI's minimum-importance filter.

The underlying CLI already supports this:

nmem memories search "query" --importance 0.7

Because the Hermes tool schema has no equivalent parameter, agents cannot ask the provider to filter out low-priority memories even when importance gating would be the right retrieval behavior.

Why this matters

Broad or high-centrality memories can still rank highly for fuzzy queries even after their importance has been lowered. For example, broad profile/history summaries may still be useful when explicitly searched, but should be easy to filter out during task-focused recall.

Without a tool-level importance parameter, Hermes agents must either:

• accept low-importance results in the tool output, or
• bypass the provider and shell out to the CLI directly.

Proposed fix

Add a min_importance parameter to nmem_search and forward it to:

nmem m search <query> --importance <min>

I have a PR ready that implements this in the Hermes provider and adds regression coverage.