## v1.13.0 (2026-09-06)

Write-module conveniences for set operations

• clear_tags(book_id) -> int detaches every tag from a book in one
  call: link rows deleted, now-orphaned tag rows pruned after (the
  fkc_delete_on_tags order), last_modified bumped and the book queued
  for OPF resync only when a link actually went away. The count of removed
  links comes back and an already-untagged book is an honest zero; until
  now a caller had to know the tags to clear them through per-name
  remove_tag.
• add_custom_column_values(book_id, label, values) -> int gives
  multi-valued custom columns append semantics. set_custom_column is
  replace-only, so putting Brandon beside an existing Rin in #audience
  took a read-modify-replace dance; the new call dedupes against the book's
  existing values (the link table is UNIQUE(book, value)), collapses
  duplicates within the input, inserts only genuinely new links, and
  returns the honest count. Scoped to is_multiple Pattern-A columns:
  single-valued and direct-storage columns raise with a pointer to
  set_custom_column, and a bare string is a TypeError rather than a
  comma-split guess.
• clear_rating(book_id) -> bool is a self-documenting alias of
  set_rating(book_id, None) so an audit trail names the operation; the
  orphaned rating row prunes with it.
• Consumers: CalibreQuarry's Phase 16 set-mode verbs and Phase 17's
  #audience step sit directly on these three calls and need nothing new
  downstream; Bindery, Hermitage, and Carrel-calibre-web are unaffected in
  their recorded postures and no Flatpak pin moves. The phase-3-import
  skill's UNIQUE(book, value) gotcha now teaches the setters instead of
  raw delete-then-insert, and the phase-1 skill was swept clean.
• The test fixture's link tables now carry the real UNIQUE(book, value)
  shape plus an is_multiple #audience column; suite 258 → 280 (the
  255 baseline here was a typo; the same-day 1.12.0 entry below says
  255 → 258 -- repaired 2026-09-09 so the two agree).