feat(author): harden reporting and claim capability per #183

- Add 'mark_issue' to TASK_MAP in resolve_task_capability for exact mutation proof (closes gap on unknown treated as allowed).
- Add assess_controller_handoff and integrate into build_final_report (downgrades missing handoff).
- Add tests for handoff and update existing.
- Update SKILL.md and review-pr.md to mandate exact 'Controller Handoff' section, exact sweep evidence, PR head SHA in reports.
- Author profile used throughout; no review/merge.

Refs #183

skills/llm-project-workflow/SKILL.md

@@ -316,11 +316,13 @@ Ready-to-copy templates live in [`templates/`](templates/):
 
 ## K. Controller Handoff (required, every task)
 
-Every LLM task **must end with a `Controller Handoff`** — whether the
+Every LLM task **must end with a `Controller Handoff`** (exact title) — whether the
 task was implementation, review, merge, issue triage, documentation,
 discussion-only, or blocked planning. It lets a controller LLM understand the
 current state immediately, without rereading the conversation.
 
+The section title must be exactly "Controller Handoff" (or "Controller Handoff Summary" for long form). Reports without it are downgraded (see review_proofs.assess_controller_handoff).
+
 **The compact format is the default.** It is written for controller-LLM
 readability, not as a full human status report. PR bodies still carry the
 full review detail — the handoff never replaces PR documentation.