fix(settings): close cross-namespace, dispatch, and lifecycle races from second review

Confirmed and fixed, each with a regression test that failed first:

- Concurrent writes to different namespaces lost whole sections on disk
  (each persist rendered the full document from a stale text): the local
  provider serializes render->write->rename->text-commit on one internal
  persist chain shared by every namespace queue.
- One throwing settings/updated listener starved the rest (cordis emit
  stops at the first throw): commit fans out per listener via
  events.dispatch, contains individual failures, and rethrows the first
  INVARIANT-coded error only after every listener ran.
- Write queues ignored fiber/service lifecycle: the base init now
  registers a teardown that refuses new writes and drains queued chains;
  queued tasks re-verify service liveness and namespace ownership before
  running and again before committing, so a registrant disposed
  mid-flight is never notified and a disposed service never commits.
- Async watcher invocations could interleave (a slow stale call applied
  last): each watcher carries a serialized invocation chain — one call
  at a time, in commit order; JSDoc/doc pages state the async timing.
- update/replace borrowed the caller's object until the queued task ran:
  inputs are structured-clone snapshotted at call time; non-cloneable
  plain objects reject with a typed error.
- Composition guard now proves the documented fallback: the consumer
  uses the optional scoped-inject shape and boots both with the settings
  entry (hot publish) and without it (entry-config resolution, no scope).
- core-data-structures index: settings.md row added to the sub-page
  table in core.md/core.zh.md.

Both packages hold per-file 100% coverage across repeated runs.

packages/settings/settings-local/tests/local.spec.ts

@@ -146,6 +146,23 @@ describe('persist', () => {
     expect((await readdir(dir)).sort()).toEqual(['settings.yaml'])
   })
 
+  it('serializes cross-namespace writes into one on-disk document', async () => {
+    const dir = await tempDir()
+    const path = join(dir, 'settings.yaml')
+    const ctx = await boot({ path, watch: false })
+    const alpha = ctx.settings.register(settingsNamespace('alpha'), ThemeSchema)
+    const beta = ctx.settings.register(settingsNamespace('beta'), ThemeSchema)
+    await Promise.all([
+      alpha.update({ theme: 'light' }),
+      beta.update({ fontSize: 20 }),
+    ])
+    const text = await readFile(path, 'utf8')
+    expect(text).toContain('alpha:')
+    expect(text).toContain('beta:')
+    expect(alpha.get().theme).toBe('light')
+    expect(beta.get().fontSize).toBe(20)
+  })
+
   it('never follows a planted symlink at a temp path and never leaves the document a symlink', async () => {
     const dir = await tempDir()
     const path = join(dir, 'settings.yaml')
@@ -209,6 +226,9 @@ describe('persist', () => {
     await chmod(dir, 0o700)
     expect((await readdir(dir)).sort()).toEqual(['settings.yaml'])
     expect(scope.get().theme).toBe('light')
+    // The failed persist must not poison the document write chain.
+    await scope.update({ theme: 'dark' })
+    expect(scope.get().theme).toBe('dark')
   })
 
   it('round-trips a json document', async () => {