uv(pass-a-r1): K-purge — Rev-4-FINAL compliance. A1: reconcile_ok replaced by stateless per-event tripwire (tripwire_ok + tripwire_last_event_id on AccountStateSnapshot). Detection latency = 1 event. A2: ASEXAccountV2.k_capital -> _k_capital_internal. 6 acceptance tests.

prod/clean_arch/dita_v2/contracts.py

@@ -408,3 +408,35 @@ class KernelOutcome:
     transitions: Tuple[KernelTransition, ...] = ()
     emitted_events: Tuple[VenueEvent, ...] = ()
     details: Dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass(frozen=True)
+class AccountStateSnapshot:
+    """Frozen value mirroring exchange account truth (E-block).
+
+    Rev-4-FINAL: E sole authority. No K-derived fields.
+    reconcile_ok kept for backward compat — consumers MUST read tripwire_ok.
+    """
+
+    wallet_balance: float = 0.0
+    available_margin: float = 0.0
+    used_margin: float = 0.0
+    event_seq: int = 0
+    mono_ns: int = 0
+    e_live: bool = False
+    # Rev-4 compat (deprecated — K-derived, do not read)
+    reconcile_ok: bool = False
+    # Rev-4-FINAL: stateless per-event tripwire
+    tripwire_ok: bool = True
+    tripwire_last_event_id: str = ""
+
+    def as_dict(self) -> dict:
+        return {
+            "wallet_balance": float(self.wallet_balance),
+            "available_margin": float(self.available_margin),
+            "used_margin": float(self.used_margin),
+            "event_seq": int(self.event_seq),
+            "mono_ns": int(self.mono_ns),
+            "e_live": bool(self.e_live),
+            "reconcile_ok": bool(self.reconcile_ok),
+        }