Merge branch 'worktree/web-carrier-chain' into worktree/web-ask-user-question

Restack the ask-user domain layer onto the carrier-chain architecture
branch. Conflict policy: runtime and ui-conversation take the
carrier-chain side (master sessions shape, dual-kind PendingCard,
'internal' envelope shell tests); the 'cancelled' wire code and its
semantics tests stay in apiproxy + ui-question (domain layer); the
smoke fixture keeps the nine-bundle success pass with the resident
question round over the carrier-chain first-describe shape.

pnpm-lock.yaml

@@ -555,9 +555,6 @@ importers:
 
   packages/client/ui-conversation:
     dependencies:
-      '@deepseek-ai/dsh-client-i18n':
-        specifier: workspace:^
-        version: link:../i18n
       '@deepseek-ai/dsh-client-runtime':
         specifier: workspace:^
         version: link:../runtime
@@ -2132,6 +2129,9 @@ importers:
       '@deepseek-ai/dsh-workflow-workerthread':
         specifier: workspace:^
         version: link:../../workflow/workflow-workerthread
+      '@deepseek-ai/dsh-workspace-context':
+        specifier: workspace:^
+        version: link:../../context/workspace-context
     devDependencies:
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^