docs(settings): third-review contracts across READMEs, catalogs, and the write-path integrity note

The seam README states the JSON-shaped write boundary, watch-disposer
quiescence, async listener containment, and the drained teardown; the
provider README rewrites Behavior around the operation chain,
read-modify-write, writer lock, ready reconcile, and leaf-level YAML
diffs, and updates Known Limitations to the residual guarantees.
A new Agent Note records the round's decisions and supersedes the
original note's deferred-lockfile alternative (cross-linked in place).
Chinese counterparts updated pair-by-pair (three briefed minimal
updates, one whole-document translation); type-equiv, config, cordis,
and module-graph catalogs re-recorded.

packages/settings/settings/README.md

@@ -9,10 +9,10 @@ Abstract user-settings seam (`ctx.settings`). One provider holds a raw document
 - `register(ns, schema, { base?, applies? })` — returns the owner `SettingsScope` (`get`/`watch`/`update`). The registration is an effect on the calling plugin's fiber: disposing that fiber removes the namespace and its observers. A stored section the schema rejects fails the registration itself; a duplicate namespace fails loud.
 - `describe()` — one descriptor per namespace (`schema.toJSON()` envelope, resolved value, `applies`) for configuration surfaces.
 - `get(ns)` — resolved value, `undefined` while unregistered.
-- `update(ns, patch)` — deep-merges the plain-object patch into the user section only (never the `base`), validates the resolved candidate, persists through the provider, then commits. Validation failure rejects before anything is persisted; a read-only provider (`writable: false`) rejects every write. Writes to one namespace are serialized in call order.
+- `update(ns, patch)` — deep-merges the plain-object patch into the user section only (never the `base`), validates the resolved candidate, persists through the provider, then commits. Patches must be JSON-shaped data: a Date, Map, BigInt, non-finite number, or circular reference rejects with its `$`-rooted path before anything persists (YAML/JSON storage would silently distort such values on reload). Validation failure rejects before anything is persisted; a read-only provider (`writable: false`) rejects every write. Writes to one namespace are serialized in call order.
 - `replace(ns, section)` — sets the user section wholesale: the removal/reset path a merge cannot express (`replace({})` re-inherits `base` and schema defaults).
-- Resolved values are deep-frozen snapshots. Watchers receive `(next, prev)` after each commit: invocations of one callback run asynchronously, one at a time, in commit order (a slow stale invocation can never apply after a newer one), and failures — sync throws and async rejections alike — are contained. The `settings/updated` event fans out one listener at a time, so one throwing listener cannot starve the rest.
-- Service teardown refuses new writes and drains every queued write before disposal completes; a write whose registrant fiber was disposed mid-flight still reaches storage but commits and notifies nobody.
+- Resolved values are deep-frozen snapshots. Watchers receive `(next, prev)` after each commit: invocations of one callback run asynchronously, one at a time, in commit order (a slow stale invocation can never apply after a newer one), and failures — sync throws and async rejections alike — are contained. After a watch disposer returns, no further invocation starts (one already queued is skipped); an invocation already started still settles. The `settings/updated` event fans out one listener at a time, so one throwing listener cannot starve the rest; an async listener's rejection is contained and logged, which is why `INVARIANT`-coded failures rethrow only from synchronous listeners.
+- Service teardown refuses new writes and watcher starts, then drains every queued write and every started watcher invocation before disposal completes; a write whose registrant fiber was disposed mid-flight still reaches storage but commits and notifies nobody.
 
 ## Provider contract
 
@@ -33,5 +33,5 @@ No direct invalidation; a consumer that folds a settings value into the request
 ## Known Limitations and Deferred Work
 
 - **Single user layer** — resolution knows schema defaults, one composition `base`, and one user document; there is no project/managed layering or per-value provenance yet.
-- **Cross-process concurrency is provider-defined** — the seam serializes writes per namespace in-process only; concurrent processes converge by provider behavior (the local file provider is last-write-wins).
+- **Cross-process concurrency is provider-defined** — the seam serializes writes per namespace in-process only; concurrent processes converge by provider behavior (the local file provider read-modify-writes under a writer lock, so namespaces survive concurrent writers and same-namespace conflicts resolve last-write-wins).
 - **No secret-field redaction** — `describe()` returns resolved values verbatim; a wire surface (RPC/UI) must redact `role('secret')` fields before exposure.