fix(feedback): address review findings in the controller and controls

Resolve the note-erasure race the review found: a control that rendered
before the first list read held no item and passed note=undefined, so
switching a rating silently dropped the stored note. The controller now
owns note resolution and toggle-vs-retract, deciding from the committed
item inside the serialized mutation, and clearNote expresses deletion.

Also from review:
- serialize the reconnect re-read behind queued mutations (resync), so a
  list reply cannot resurrect a version a newer mutation replaced
- re-check disposal after the seeding read, so an unloaded fiber never
  reaches the wire
- drop Object.freeze on Maps, which does not prevent set/delete
- declare the @deepseek-ai/dsh-client-connection dependency it imports
- surface a failed list load in the controls
- drop the /client value exports that had no consumer
- state the per-turn render scope in the README and subsystem pages
- align the package version with the root

pnpm-lock.yaml

@@ -2204,6 +2204,9 @@ importers:
       '@deepseek-ai/dsh-api-remotes':
         specifier: workspace:^
         version: link:../../api/remotes
+      '@deepseek-ai/dsh-client-connection':
+        specifier: workspace:^
+        version: link:../connection
       '@deepseek-ai/dsh-client-locale':
         specifier: workspace:^
         version: link:../locale