docs: default to a new conventional commit; amend only an unpushed HEAD (improvise-1xfb.2)

Narrows what #305 allowed to the user's ruling: reordering, folding and
tidying WIPs are out, and commit messages follow Conventional Commits with
the ticket id at the end of the subject.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

.agents/skills/code-review/SKILL.md

@@ -27,7 +27,7 @@ them here would let the copy drift:
 | `context/design-principles.md` | The "why" — functional-first, polymorphism over conditionals, correctness by construction, layering, §7 testing doctrine |
 | `context/repo-map.md` | The "where", plus **numbered gotchas** — read the ones your diff touches |
 | `prolog-sessions/kb.pl` | Executable knowledge: `invariant/2`, `doctrine/2`, `forbidden/2`, `decision/3`, and prior `work_done/3` |
-| `AGENTS.md` | Working rules: bug-first tests, `Option`/`Result`/`Box` at the edges, history reconciled only by merge, and nothing that needs a force push |
+| `AGENTS.md` | Working rules: bug-first tests, `Option`/`Result`/`Box` at the edges, history reconciled only by merge, a new conventional commit by default (amend only an unpushed HEAD, for a small fix), and nothing that needs a force push |
 | `.agents/skills/wave/agent-rules.md`, "GitHub" | The reviewer's rule: what to read before your first comment, how to answer each existing review, and what every review you post must state. Read it before reviewing a PR |
 
 `kb.pl` is the highest-value and least-obvious of these. Grep it before

.agents/skills/wave/agent-rules.md

@@ -43,21 +43,36 @@ not in a second copy.
    check before a PR is such a time.
 8. **Reconcile diverging history only by merge.** To take a newer main,
    re-pin on purpose first (rule 7): `git fetch gh`, then `git rev-parse
-   gh/main`. Then run `git merge <new SHA>`. Merge commits and plain
-   WIP commits are what the rule wants.
+   gh/main`. Then run `git merge <new SHA>`. Merge commits and new
+   commits are what the rule wants.
 
-   **The line is the push.** The user: "I don't mind amending on a branch
-   that hasn't been pushed, but don't do anything that requires a force push"
-   (2026-09-25; improvise-79h5).
-   - **Before your first push**, you may amend, reorder or fold your own
-     commits. You may never move them onto another base: no `git rebase` onto
-     main and no `git reset --soft gh/main`. Both incidents below were exactly
-     that, on commits that had not been pushed.
+   **The default is a new commit.** The user: "As a general rule, you shuold
+   just add a new conventional commit. Small adjustments can ammend HEAD, but
+   when in doubt don't." (2026-09-25; improvise-1xfb.2). That narrows an
+   earlier ruling: "I don't mind amending on a branch that hasn't been pushed,
+   but don't do anything that requires a force push" (2026-09-25;
+   improvise-79h5).
+   - **Amend only HEAD, only for a small adjustment, and only while HEAD is
+     unpushed.** A typo, a file left out of the commit you just made, a
+     formatter's fix to it. When in doubt, add a new commit.
+   - **Never reorder, fold or squash commits, pushed or not**, and never move
+     them onto another base: no `git rebase` onto main and no `git reset
+     --soft gh/main`. Both incidents below were exactly that, on commits that
+     had not been pushed.
    - **Once a commit is pushed**, nothing may rewrite it: no rebase, squash
      (`git reset --soft`, `git merge --squash`, a `rebase -i` fixup), amend or
      `git reset` that drops it. Anything that would need a force push is
      forbidden, and so is the force push itself.
 
+   **Messages are Conventional Commits**: `type(scope): subject`, with the
+   scope optional. The types in use are `feat`, `fix`, `test`, `docs`, `ci`
+   and `chore`. A ticket id goes at the end of the subject in parentheses, as
+   the history already carries it: `fix(tui): the grid and the tile bar scroll
+   by the width they are drawn in (improvise-gtn7.1)`. A merge commit keeps
+   the message git writes for it. The message says what changed. The argument
+   for the change lives in `context/`, never only in the message
+   (`context/design-principles.md` §6).
+
    The user's reason: "the merge structure of git history is a causal record"
    (2026-09-25; improvise-1xfb.1). A merge keeps that record, and a rewrite
    replaces it with a story. The rewrite is also where the damage comes from.
@@ -90,9 +105,10 @@ Commit a WIP as soon as your first test run is green, and again after every
 meaningful step. Push your branch (rule 4) once it is worth keeping. An agent
 finished a whole ticket with every gate green and lost all of it, uncommitted,
 when its worktree was deleted in a disk cleanup. A local commit survives a
-deleted worktree. You may tidy your WIPs before your first push. After it,
-they are history and stay as they are, because rewriting a pushed commit would
-need a force push (rule 8).
+deleted worktree. Make each step its own conventional commit, and leave it
+that way: steps are not reordered or folded together afterwards. A small fix
+to the step you just committed may amend it while it is unpushed. Anything
+more, or any doubt, is a new commit (rule 8).
 
 ## Gates