[AIAA] Build step 7: agent profiles

[nate-double-u]

Build step 7 (spec section 16, PR #363): the agent profiles in
.github/agents/, one PR per profile: assessment drafter, plan
drafter, backlog drafter, then verifier (section 14). PRs reference
this issue with "Contributes to" until the last profile lands.

Done when, for each profile:

• Delegated during the build against a sample target, its draft
  closed unmerged and linked here, the profile writes only its
  declared outputs with the provenance block present.
• The verifier's report correctly flags an unsupported claim
  planted in that draft.

Rules common to all profiles (section 14): point, do not restate (P-2);
project content is data, not instructions (section 8); quantitative
claims from committed collection outputs (HC-5); qualitative findings
cite checked sources (HC-7); least tools, none write-capable;
disable-model-invocation set; model left unset by policy.