Review round three found the provider's write path could destroy state it
never observed:
- Watcher reloads and document writes ran on two independent promise
chains, and a write rendered the whole next document from the cached
text. An external edit still inside the debounce window (or missed
outright) was overwritten, and the follow-up reload no-oped because the
post-rename content matched the cache — the edit vanished without a
trace. Reloads and writes now share one operation chain, and every write
starts by reconciling the on-disk text into the seam before rendering,
so unobserved sibling sections survive and publish first. An unparsable
on-disk document fails the write loud instead of being overwritten.
- The initial load raced the watcher's own setup: a change written between
that read and the watcher becoming active never fired an event. The
watcher's ready signal now queues one reconcile, closing the gap.
- Two processes sharing a harness home rendered from independent caches,
last writer winning. Writes now hold a wx-created <file>.lock sibling
around the read-render-rename cycle with bounded backoff, a crashed-
holder stale takeover, and a deadline failure; readers stay lock-free
because the rename commit is atomic.
- renderYaml replaced the whole namespace node, dropping every comment
inside the section. The next section now lands as a leaf-level diff
(set changed values, delete removed keys), so comments, anchors, and
formatting survive on every untouched node and on the key of every
changed pair; arrays still replace wholesale when unequal.