Small UI fixes from the #262 live pass #297

Found in the #262 live pass (evidence):

• Archive warning dialog: a double period ("…then stop.."). J5-owned copy.
• A Codex saved-agent draft (for example Scout routed to Codex) lists Claude slash commands in the composer. Commands should follow the draft's resolved provider.
• Console: a React warning about a spread key prop in ChatView, and one "Maximum update depth exceeded" error during a two-tab steer race. Check whether either comes from a J5 delegate; if it's upstream, add it to Upstream give-back backlog (hold until V2 merges upstream) #276.