feat: persist local reviews automatically in SQLite

src/main.rs

@@ -87,8 +87,9 @@ Local reviews: :diff.comment anchors exact Visual text, Visual Line rows, or the
       Selected comments highlight their precise text
       :diff.review.edit/delete [ID], :diff.review.next/previous, :diff.review.overview
       :diff.review.summary; :diff.review.verdict looks_good|changes_requested|none
-      :diff.review.save PATH / :diff.review.open PATH; :w in floating review editors saves local JSON
-      Normal Esc or :pane.close dismisses the floating editor and retains drafts
+      Local SQLite autosave on dismissal/switch; verdicts/deletions commit immediately; :w commits explicitly
+      :diff.review.save PATH exports JSON; :diff.review.open [ID|PATH] selects/imports; :diff.review.new
+      Normal Esc or :pane.close commits and dismisses the floating editor; failures retain drafts
       Snapshot anchors stay immutable; stale comments lose gutter markers; no publishing
 Pull requests: :pull_requests [REMOTE]; GitHub/GitLab/Gitea Open/Closed/All tabs, type to search
       Enter opens the immutable PR head against its merge base; API auth uses provider tokens or gh/glab