docs: require Controller Handoff Summary + codify LLM workflow rules (#101)

- SKILL.md: new §K Controller Handoff Summary (required every task type)
  with the exact format and a worked blocked-handoff example; issue-first
  rule extended (discussion/RFC issues, unclear-tracker-home stop rule, no
  new repo/tracker without owner approval); merge workflow now names
  identity+author verification, profile gates, independent validation, and
  pinned head SHA / expected changed-file merges; tagging rules extended
  (no tag ops unless instructed, tag only the verified final master merge
  commit, always report tag target).
- llm-workflow-runbooks.md: Controller Handoff Summary section pointing at
  SKILL §K, incl. discussion/RFC rule (e.g. #100 stays a discussion issue).
- templates/start-issue.md + review-pr.md: handoff lines now reference the
  required summary format and the exact-gate reporting rule.

Docs only; no code behavior changed. No tags touched; #100 not modified.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

skills/llm-project-workflow/templates/start-issue.md

@@ -36,5 +36,7 @@ Steps:
    - Self-review allowed: no
 8. Stop before review/merge — you are the author.
 
-Handoff: issue #, branch, worktree path, files changed, checks + results, PR URL.
+Handoff: issue #, branch, worktree path, files changed, checks + results, PR URL —
+formatted as the Controller Handoff Summary (SKILL.md §K); end with
+"Review needed — PR is open".
 ```