docs: one home for the review rules; pin gh/main; audit prose fixes

improvise-28ri: -d skip only silences "Is a directory" on the skills'
symlinks, which git ls-files lists as files. grep -r never follows them,
so nothing was ever read twice. The "spells no id" sentence now says what
the recipe actually cites.

improvise-oga4: the review-reply and head-SHA rules live only in
agent-rules "GitHub" (plus the after-merge clause moved there); AGENTS.md
points to it, and the code-review skill names it. An ADR's "Approved" is
an extra gate on top of CI, every review answered and the adversarial
review.

improvise-diho: agent-rules rule 7, pin gh/main to a SHA at task start.
Also: build a test-name list in a fresh CARGO_TARGET_DIR, because
git archive's commit mtimes make a reused one return a stale list.

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

@@ -28,6 +28,7 @@ them here would let the copy drift:
 | `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, merges over rebases |
+| `.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
 reviewing: `grep -n "invariant(\|doctrine(\|decision(" prolog-sessions/kb.pl`.

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

@@ -32,9 +32,17 @@ not in a second copy.
 6. **The Beads "Session Completion" block near the end of `AGENTS.md` does not
    set your git policy.** This repository does not opt in to the block's
    "team-maintainer" profile. On a wave branch that profile's pull and bare
-   `git push` would be refused (rule 4), or worse. Rules 1–5 are your git
-   policy. The block is bd's and bd regenerates it whole, so it is not edited
-   by hand: `AGENTS.md`, "Repository policy over the Beads blocks" (improvise-x1uk).
+   `git push` would be refused (rule 4), or worse. Rules 1–5 and 7 are your
+   git policy. The block is bd's and bd regenerates it whole, so it is not
+   edited by hand: `AGENTS.md`, "Repository policy over the Beads blocks" (improvise-x1uk).
+7. **Pin `gh/main` to a literal SHA when the task starts.** Run
+   `git rev-parse gh/main` once. Use that SHA, not the ref name, for every
+   reset, merge-base and diff. Remote refs are shared by every worktree of the
+   repository, so `gh/main` moves whenever another session fetches. An agent
+   ran `git reset --soft gh/main` mid-task and staged a reverse diff of #196.
+   It noticed only because it read `git status` (improvise-diho). Re-resolve
+   only on purpose, for example when you mean to merge a newer main. Rule 3's
+   check before a PR is such a time.
 
 ## Commit early: a worktree is not durable storage
 
@@ -113,6 +121,12 @@ out on purpose:
   check that no test *disappeared*. Diff test **names**, not counts: a
   textually clean merge can delete a test module with no conflict marker, and
   the other side's new tests mask the loss in a count.
+- **Build each side's test list in a fresh `CARGO_TARGET_DIR`, every time.** If
+  a parent's tree comes from `git archive`, a reused target dir gives a wrong
+  answer, not just a slow one. Archive stamps every file with its commit time,
+  so cargo judges the sources older than the last build and lists the previous
+  tree's tests. On #188 that made three of the branch's own tests look
+  merge-only.
 - **The shell guard refusing a compound command means NEITHER part ran.** Split
   the command. After a refusal, re-check the state it was meant to produce.
 - **Re-run the full suite after reverting an injected fault.** A revert applied
@@ -200,6 +214,8 @@ text for any of these in your hand-back.
   `./scripts/pr-reviews <n>`, unpiped. Reply on its thread to every Codex
   review: fixed (name the commit), declined (say why), or already one of our
   tickets (name it). Every review you post states the head SHA it reviewed.
+- **Answer a review even if the PR has already merged.** Reviews arrive late,
+  and the thread is still where the next reader looks.
 - **Do not merge, and do not close beads.** Your part ends at an open PR plus
   your hand-back. What "done" means is in `AGENTS.md`, "Repository policy over
   the Beads blocks". Avoid stacked PRs. If you must stack, never let the base