[pengusto]

fix: warn when the export limit leaves repositories unprocessed

Summary

The default EXPORT_LIMIT=10 can leave most starred repositories unprocessed on every run. Log a warning when the limit is reached and more repositories remain, including how to disable the limit. Clarify in the README that each run starts from the beginning.

The default limit and export behavior stay unchanged. No warning is logged when the limit covers all repositories or the limit is disabled.

Evidence

• go test ./... and go vet ./... passed in the project's Go 1.27 Alpine environment.
• Four cases exercise the actual exporter with mocked HTTP responses: a truncated run, exactly at the limit, no limit, and an invalid repository before the limit.
• Against unchanged upstream, the two truncated-run cases fail because the warning is missing; with this change all four pass.
• No live GitHub or Karakeep account was used by the tests.

Merge Danger

Door: Two-way. The change adds a log message and documentation; it does not change the limit, exported repositories, scheduling or stored data.

Blast Radius: Logging. A deliberately limited run with remaining repositories emits one extra warning per run.

An LLM assisted with the implementation, tests and description.

[hasansino]

This is intended behaviour. It is documented.