background jobs: start silently, say one line

Asking for `bun dev` produced a preface ("Starting it exactly as specified…"), the
call, a read-back of the output to confirm, a paragraph explaining what resolved
to what, and then two unsolicited notes. Five kinds of output for a request whose
whole appeal is that there is nothing to discuss.

The preamble already said "tell me in one line" and was talked past, because it
described the ending without forbidding the rest. Now it names each thing:

  - nothing before starting — no preface, no restating the ask, no announcing
    that the instructions are about to be followed
  - one line after: what is running, its id, how to stop it. Not notes, not
    observations, not what was chosen or why, not anything noticed in passing
  - a question is the ONLY thing allowed to come first

And it no longer reads the output back to check the job started. That was work
the harness already does: if it fails, the exit arrives on its own — which is the
entire reason for using the tracked mechanism. Verifying by hand adds noise to
the one case where nothing is wrong, and adds nothing to the case where something
is.

Silence stays conditional, not absolute: an unclear condition must still be
settled in conversation before anything is armed.

tsgo clean, frontend builds, 851 pass / 7 fail unchanged.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/workspaces/officerdev/src/apps/Chat/background-job-prompt.ts

@@ -106,6 +106,19 @@ export function buildBackgroundJobPrompt(spec: BackgroundJobSpec): string {
     `condition fails silently: it either never fires or fires constantly, and I find out days later.`,
     `Arming it late costs a minute; arming it wrong costs whatever I was relying on it for.`,
     ``,
-    `When it is armed, tell me in one line what you started and how to stop it.`,
+    `A question is the ONLY thing that may come before starting.`,
+    ``,
+    `OUTPUT:`,
+    ``,
+    `Say nothing before you start it. No preface, no restating what I asked for, no announcing that`,
+    `you are about to follow the instructions.`,
+    ``,
+    `Then ONE line: what is running, its background id, how to stop it. That is the whole reply.`,
+    `No notes, no observations, no explaining what you chose or why, nothing you happened to notice`,
+    `along the way. If any of it mattered I would ask.`,
+    ``,
+    `Do not read the output back to check it started. If it fails, the exit reaches me on its own —`,
+    `that is the entire point of using the harness's mechanism, and checking by hand just adds noise`,
+    `to the one case where nothing is wrong.`,
   ].join('\n');
 }