diff --git a/AirPlan/docs/architecture/system-detailed-design.md b/AirPlan/docs/architecture/system-detailed-design.md
index 1378bac..308c1e3 100644
--- a/AirPlan/docs/architecture/system-detailed-design.md
+++ b/AirPlan/docs/architecture/system-detailed-design.md
@@ -2275,14 +2275,28 @@ classDiagram
     ArchitectureDesigner --> EventIngestor
 ```
 
-## 23. Design Freeze Checklist
+## 23. Design Freeze Declaration
 
-Before implementation begins, verify:
+**System Detailed Design is frozen as of 2026-06-01 (commit `2673e49` → this commit).**
+
+Multi-model review complete: DeepSeek (R1, R7) / MIMO 2.5 Pro (R2) / GPT-5.5 Pro (R3) /
+Opus 4.8 (R4, R6) / Opus 4.7 (R5 regression). All P0/P1/P2 findings closed
+across 7 review rounds. Coverage: contracts 100%, events 100%, DB schema 100%,
+state machines 100%, forbidden edges 100%.
+
+**Design-level verification (complete — verified in review):**
+
+- [x] All contracts §2-§21 interfaces mapped to DD classes (§21.1)
+- [x] All db-schema §3-§18 tables have corresponding repositories (§4.3, §21.3)
+- [x] All event-registry §3 durable events have projection handlers (§5.4)
+- [x] All state machines specified (Main Agent / Scheduler / Task / Agent / Workspace / Capability, §20)
+- [x] FK-off invariants defined (§18.3 ≡ runtime-semantics §14)
+- [x] Outbox model defined (§18.4)
+- [x] Security invariants defined (§18.5)
+
+**Implementation-entry gates (to be verified as code is written):**
 
 - [ ] All contracts §2-§21 interfaces are exported from `packages/contracts`
-- [ ] All db-schema §3-§18 tables have corresponding repositories
-- [ ] All event-registry §3 durable events have projection handlers in EventStore
-- [ ] All state machines (Main Agent, Scheduler, Task, Agent, Workspace, Capability) are implemented
 - [ ] All forbidden paths (contracts §23) are enforced by lint/import boundaries
 - [ ] All closed enums (db-schema §21) are validated on insert/update
 - [ ] FK-off invariants (§18.3) are checked at startup and periodically
@@ -2291,4 +2305,4 @@ Before implementation begins, verify:
 
 ---
 
-End of System Detailed Design.
+End of System Detailed Design (frozen).