WriteOperation replaces free-form operation strings throughout
BoardWriter, per the settled rule in 02 § Write-failure surfacing: the
banner layer will switch exhaustively over it, so a new operation
without a banner rendering is a compile-time hole. Titles enrich at the
two points a document read makes them known (updateIndex, and the
move/copy pre-flight), so failures after the read name the item;
purge never reads and stays title-less. Free-form English survives
only in the diagnostic reason.
Full suite 300 tests in 56 suites green.
Claude-Session: https://claude.ai/code/session_018BjQRYBR6jQja3jCRi5S3A
The executable spec for BoardWriter's cross-cutting guarantees, in a
dedicated WriteFidelityTests.swift: minimal-touch verified down to
sibling mtimes across a seven-operation session; renumber pinned as
the sole exception (whole lane rewritten, board root / other lanes /
tombstones untouched); delete→restore byte-precise (only the modified
line differs, zero tombstone residue); unknown-key order preserved
with keys interleaved among schema-owned ones; and a composite
building a board purely through the writer, hand-editing a file like
an agent would, then moving/copying/deleting/renumbering to a
zero-warning reload. Guarantees already pinned by the per-operation
suites (atomicity, move/copy identity, body round-trip) are
referenced, not duplicated. Shared fixtures promoted to
WriterTestSupport.swift. README gains the write-side feature bullet.
5 new tests; 250 total green. Closes milestone m2-storage-write.
Claude-Session: https://claude.ai/code/session_018BjQRYBR6jQja3jCRi5S3A