diff --git a/CLAUDE.md b/CLAUDE.md
index 11e4a643..c5c4d334 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -150,6 +150,29 @@ StatMod parse — mid-session buffs inert until relog), and matrix rows
 step. Vendor browsing (Slice 5) and authoritative vendor transactions
 resume after Campaign P closes.
 
+**Placement cutover — C4 COMPLETE 2026-08-05, merged to main.** Every
+placement route now runs through the canonical residence + continuation-
+executor owner. Routes landed this session: 4b-3 remote teleport/cell-less
+(`6dc7ba51`), 6 drops (`1b484937`, zero production lines), 5 projectile
+(`36255af0`), 7 child-cell propagation (`cd3129e9`), 3 portal
+(`e0f96a55`), plus the `OnPosition` dual-tail collapse (`edc911b0`) that
+retired the duplication behind three separate defects. Suite 11,027 →
+**11,090 passed / 4 skipped / 0 failed**. Connected gates: routes 3, 6 and 7
+user-passed 2026-08-05 with probe evidence; route 7's is THIN (one
+`cause=propagate`) and 4b-3's `cause=cellless` case remains unrun with an
+UNESTABLISHED trigger — route 7 invalidated its recorded recipe.
+
+**Read `docs/research/2026-08-05-c4-closeout-handoff.md` before any C5 or
+placement work.** It carries the four gate recipes, what C5 inherits (#318's
+composition test and its discriminating assertion, AP-145, the #276/#277
+remainders, the probe-family strip), and seven process findings with commits
+attached. The two that cost the most this campaign: a contract asserting a
+mechanism that does not exist caused three separate defects, and inferring a
+fact you can observe made one fix strictly worse than the bug it replaced —
+it removed the invariant failure while leaving the bug. Next: C5 (delete the
+superseded legacy paths, retire AP-1/AD-1, parity tests), then #280, AP-22,
+AD-10.
+
 **Modern Runtime/performance status:** Slices A–K of
 `docs/plans/2026-07-24-modern-runtime-architecture.md` are complete. Slice L is
 parked at its L1 implementation checkpoint by user direction on 2026-07-27.