Obsidian sync

The sync Lambda runs on a 5-minute EventBridge schedule.

1. Clone (or pull) the Obsidian vault git repo into /tmp.
2. Walk every *.md file, content-hash it.
3. For each file whose hash changed since the last sync, parse it and upsert the page through the same Store the API uses.
4. After all pages are upserted, resolve wikilinks across pages so forward references in the walk order still create backlinks.
5. Rebuild the inverted search index and upload it to the search S3 bucket.

Write-back (db -> vault) is best-effort and runs at the end of each sync.

Related: architecture · home · #meta #sync