v1.2.3

Reliability release from a full-project code review. No new features — data-safety
and correctness fixes plus two control-panel display fixes.

Fixed

• Data safety: A malformed (invalid-UTF-8) byte in entry content can no
  longer truncate the link index, indexer state, or auto-link rules to an empty
  file. JSON writes now verify the payload encoded and reached disk in full
  before replacing the existing file; on failure the previous file is kept.
• Indexing: Saving a draft — or unpublishing an entry — no longer adds it to,
  or leaves it in, the link index when the index is set to published entries only.
  The incremental save path now matches a full Scan Content.
• Broken-link checker: Far fewer false positives. Servers that reject HEAD
  but serve GET fine (common behind WAFs/CDNs) are now confirmed with a GET
  before being flagged, and a momentary timeout or connection error is no longer
  cached as "broken" for 24 hours — the next scan re-checks it.
• Auto-link rules: Editing a rule's keyword to one that already exists is now
  rejected with a clear message, matching the check that already applied when
  creating a rule.
• Links Report: The completion toast for inbound/outbound link insertion now
  shows the entry name instead of being blank.