Merge remote-tracking branch 'origin/master' into worktree/custom-deepseek-models

# Conflicts:
#	packages/host/apiproxy/README.i18n.yaml

apps/web/tests/snapshots/bash-abort-row/ui.expected.md

@@ -7,8 +7,9 @@
 - text: "Run two shell commands: wait for cancellation, then write skipped.txt. {{date}} {{clock}}"
 - button "Copy":
   - img
-- button "Branch into a new conversation":
+- button "Branch into a new conversation" [disabled]:
   - img
+- text: Available only on the last message of a completed turn
 - button "Context injection":
   - img
   - img