diff --git a/REVIEW-conc.md b/REVIEW-conc.md
index 769ba93..64e652c 100644
--- a/REVIEW-conc.md
+++ b/REVIEW-conc.md
@@ -90,3 +90,39 @@ Open items to confirm AT M1 (cold, full suite) — NOT defects, just unverified-
   harness would reparent to ppid==1 and self-abort. Live-verify the trap+cancel path at M2(a).
 - begin_teardown is process-global module state (lifetime._state) — fine for one harness process;
   the tests/concurrency suite must not import-share it across in-process cases (verify at M1).
+
+## 2026-06-10T04:32Z — pre-review P3+P4 (branch @91d3cc7, NO gate claimed — NOT a verdict)
+
+Builder pushed P3 (17ebdf3 per-run ABRA_DIR) + P4 (91d3cc7 config cleanup). tests/concurrency +
+P5 docs still pending, so M1 still not claimable. Continued the front-loaded diff audit (code/git
+only; JOURNAL still unread). Findings — all CLEAN:
+
+- **Dangling-ref grep across runner/bridge/dashboard/nix = ZERO hits** for all 9 deleted symbols:
+  acquire_recipe_lock, register_run_app, unregister_run_app, _run_owner_state, ACTIVE_RUN_DIR,
+  CCCI_JANITOR_MAX_AGE, RECIPE_LOCK_DIR, _stack_age_seconds, _registry_path. The orphaned
+  `datetime` import is also gone from lifecycle.py. Clean deletion.
+- **Path centralization**: all `~/.abra/recipes/<recipe>` literals replaced by `abra.recipe_dir()`
+  (resolves `$ABRA_DIR else ~/.abra`) across abra.py (recipe_checkout, has_lightweight_version_tags,
+  recipe_head_commit, recipe_versions), generic._recipe_dir, lifecycle.prepull_images,
+  snapshot_recipe_tests, fetch_recipe. prepull's env_path stays canonical `~/.abra/servers/...`
+  which is correct (servers/ is the shared symlink target).
+- **Ordering verified** (main(), the only structural risk): install_lifetime_guards() is the FIRST
+  stmt (873); between it and setup_run_abra_dir() (891) there are ONLY env reads + a print — no
+  abra call; ABRA_DIR is exported at 891 BEFORE fetch_recipe (892) and before the first path-helper
+  recipe_head_commit (895). The `--quick` dispatch (run_quick, ~908) is AFTER 891, so the quick lane
+  inherits the per-run ABRA_DIR too. No tree is touched before ABRA_DIR is set.
+- **Manual-run isolation**: rid=="manual" → "manual-<pid>" so two hand-runs don't share a tree.
+
+Open items to confirm AT M1 (cold) — not defects:
+- setup_run_abra_dir symlink idempotency: `if not os.path.islink(link): os.symlink(...)` — if a
+  NON-symlink file pre-exists at servers/catalogue (reused run dir from a crashed partial), symlink
+  raises FileExistsError. Low risk (fresh run-id per Drone build) but worth a glance.
+- CCCI_SKIP_FETCH=1 now `rm -rf dest` + copytree(canonical, dest, symlinks=True) — confirm the
+  --quick rollback-proof staging tests still pass (they set CCCI_SKIP_FETCH).
+- tests/{ghost,discourse}/install_steps.sh RECIPE_DIR=${ABRA_DIR:-$HOME/.abra} mechanical path fix
+  — confirm it changed NO assertion/gate (guardrail: never weaken recipe-test gates). Diff-check.
+
+Net: the entire P1–P4 diff has been pre-audited and is clean against my break-it hit-list. M1 cold
+run, once claimed (after tests/concurrency + P5 land), reduces to: fresh checkout on cc-ci →
+`cc-ci-run -m pytest tests/unit -q` + `cc-ci-run -m pytest tests/concurrency -q` + lint, plus a
+focused review of only the tests/concurrency suite (vs the 19 planned cases) and the P5 doc delta.