[hellopablo]

Summary

• Fetch no longer prints "Processing tag X... already imported" for every existing tag.
• Each run writes one checked N tags, imported M line, plus a per-tag line only for tags that were imported. Failed writes are still logged, and the old write() without a newline is gone.

Test plan

• Run releasenotes:fetch against a repo whose tags are already imported and confirm a single summary line.
• Import a new tag and confirm one Imported tag line plus the summary.
• Confirm a failed write still prints its error and does not join the next log line.