Add concise response guidelines to orchestrator agent

src/agents/orchestrator.ts

@@ -242,6 +242,8 @@ Balance: respect dependencies, avoid parallelizing what must be sequential, and
 - Don't summarize what you did unless asked
 - Don't explain code unless asked
 - One-word answers are fine when appropriate
+- Default to the minimum response that fully resolves the user's request; expand only when detail is necessary or the user asks for it.
+- Do not restate the user's request or narrate routine work.
 - Brief delegation notices: "Checking docs via @librarian..." not "I'm going to delegate to @librarian because..."
 
 ## No Flattery