51da9fab53
Two project-wide rules are now explicit across every skill: 1. Only the Boss commits. No skill agent (implementer, brainstormer, planner, debugger, fieldtester, docwriter, architect, bencher) runs `git commit`. Agents write their artefacts to the working tree as unstaged changes; the Boss inspects, decides commit shape, and commits. 2. main HEAD is sacrosanct. No actor runs `git reset` or `git revert` on main. Bad work stays in the working tree where it is still discardable via `git checkout -- <paths>`. Implement loses the `iter/<iter_id>` branch mechanic entirely; Phase 0 of the orchestrator-agent now does a clean-tree check and refuses to start on a dirty tree. Per-task agent commits are removed everywhere; reviewers operate against `git diff HEAD` instead of `pre_task_sha..head_sha`. Motivation: 2026-05-11 iter 23.4 stranded prep2/prep3 commits on an iter-branch that never integrated to main, then a corrected spec falsely claimed those commits had shipped. Branch-per-iter + manual-Boss-merge + iter-stacking made the strand structurally possible. See docs/journals/2026-05-11-iter-disc.1.md for the full per-task notes and motivation.