Added repo data check to reduce github access

[VisLab]

No description provided.

[Copilot]

Pull request overview

This PR adds a directory-level “repo data check” gate to hed.schema.hed_cache.get_available_hed_versions() to reduce GitHub API traffic by skipping per-folder crawls when standard_schema/ or library_schemas/ hasn’t changed since the last crawl.

Changes:

• Added path-scoped “latest commit SHA” gate checks (standard vs library) plus a repo_check_interval option to reduce how often those gates are queried.
• Added integration tests validating the new gating behavior using live GitHub responses (no mocking).
• Added user-guide documentation describing schema/listing caching behavior and rate-limit mitigation options.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 5 comments.

File	Description
hed/schema/hed_cache.py	Adds path-scoped commit-SHA gate checks and repo_check_interval to avoid unnecessary per-folder crawls.
tests/schema/test_hed_schema_io.py	Adds tests for the new gating behavior and cache effects.
docs/user_guide.md	Documents schema caching, listing behavior, and rate-limit mitigation guidance.
.context/plan.md	Updates plan history entry.