docs(issue-42): review - attach names the herdr server, --dry-run is not "write nothing", a deleted block stays deleted

Merge-workspace review of PR #46 (codex R1-R3 and C1, claude O1 and O4).

- R1: resume never attaches, and the server it exports does not reach the
  calling shell; the native herdr binary does not route on environment
  variables. The attach advice and the Verification block now name the
  server: `herdr --session <server> agent attach <name>`, with <server> the
  row's herdr_session.
- R2: --dry-run in resume and create skips the spawn and the registry
  update, but the checks before it still run and on macOS remove the
  quarantine attribute from the agent binary. The option rows say so.
- R3: test_no_deleted_body_came_back compares every current block with the
  deleted bodies by exact sha and by a whitespace-insensitive fingerprint
  (stored as base_fingerprint), independently of the inventory, so a
  deleted block cannot return by being listed again under class c.
  Replaying the review's probe (the deleted resume Workflow re-added and
  inventoried as c) fails the new test and passes the old one.
- C1 / O1: the base create call block at 263-266 (class c) folded into the
  Workflow call is recorded under "superseded"; the 37 base blocks are all
  accounted for.
- O4: create exit 42 also covers MAM_KILL_ON_READY_TIMEOUT=1; stop's no-op
  exit 0 does not apply with --purge-conversation.
- The inventory's positions and shas are regenerated for the edited blocks;
  every classification is unchanged.

No product code changed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

.agents/skills/multi-agent-mux-stop/SKILL.md

@@ -58,7 +58,7 @@ bash .agents/skills/multi-agent-mux-stop/scripts/stop_session.sh \
 
 | Exit | Meaning |
 |---|---|
-| 0 | Stopped; or already `stopped` (no-op) |
+| 0 | Stopped; or already `stopped` (no-op, except with `--purge-conversation`, which still purges) |
 | 1 | From the checks before the stop, nothing was changed: YAML not found, or the session is not registered. **The registry update after the stop also exits 1** (the row disappeared from the YAML during the run) |
 | 2 | Bad arguments (including the retired `--mode` / `--capture-id` / `--graceful`), or `--agent` omitted and not resolvable |
 | 3 | `--purge-conversation` without `--yes` |