agy sessions fail on agy 1.3.3: pass the prompt as -p's value #658

What to build

Since agy 1.3.3 (9 October), -p takes the prompt as its value. The agy Harness adapter puts -p first and the prompt last, so every agy session, new or resumed, now exits at once with:

Error: -p took "--dangerously-skip-permissions" as its prompt, so the intended prompt was left as an argument and ignored.

The #429 replays hit this on their first five agy sessions; the replay script fixed it by putting the prompt right after -p (see docs/research/second-opinion-replays.md, "Found along the way").

Pass the prompt, with its skill loading, as -p's value, for both a new session and one resumed with --conversation.

Acceptance criteria

• The adapter builds -p <prompt> with the prompt as -p's value, for new and resumed sessions, and its tests show that order.
• A real agy 1.3.3 session started through thirdshift receives its prompt and runs (e.g. a short prompt with the cheapest Model).
• Anything else in thirdshift that builds an agy command line (if any) uses the same order.

Blocked by

None (can start immediately).