Snapshot PINK DITAv2 system + Sprint 0 flaw-fix verification

First commit of the previously-untracked PINK-on-DITAv2 migration system
(execution moves to the Rust kernel; policy stays on legacy DITA, so Alpha
Engine algorithmic integrity is preserved). BLUE is untouched.

Sprint 0 (safety snapshot + flaw-fix verification, MARKET single-leg scope):
- Verified Rust FSM fixes (flaws 2,4,10,11,13) by source read of lib.rs.
- Hardened 5 vacuous/guarded assertions in test_flaws.py so each flaw test
  genuinely exercises its fix. Most important: Flaw 5 now asserts capital
  moves by EXACTLY realized PnL (was entering/exiting at the same price).
- Offline suites: 533 passed, 0 failed (35 flaws + 402 kernel/accounting/
  bridge + 96 runtime/persistence/multi-exit/restart/seams).
- GATE PASS: MARKET-path-critical flaws 1,2,5 confirmed fixed + green.
- Added SPRINT0_FLAW_VERIFICATION.md report and _rust_kernel/.gitignore
  (excludes Rust target/ build artifacts).

LIMIT/partial-fill remain explicitly out of scope (MARKET-only bring-up).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

prod/clean_arch/dita_v2/journal.py

@@ -0,0 +1,102 @@
+"""Debug journaling surfaces for DITAv2."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from datetime import datetime, timezone
+from typing import Any, Callable, Dict, List, Optional, Protocol
+
+from .contracts import KernelTransition, TradeSlot, TradeStage, VenueEvent
+from .control import KernelControlSnapshot
+from .utils import json_safe, json_text
+
+JournalSink = Callable[[str, Dict[str, Any]], None]
+
+
+class KernelJournal(Protocol):
+    """Append-only debug journal interface."""
+
+    def record(self, row: Dict[str, Any]) -> None:
+        ...
+
+    def record_transition(
+        self,
+        *,
+        transition: KernelTransition,
+        slot: TradeSlot,
+        event: Optional[VenueEvent] = None,
+        control: Optional[KernelControlSnapshot] = None,
+    ) -> None:
+        ...
+
+
+@dataclass
+class MemoryKernelJournal:
+    """In-memory journal used in tests."""
+
+    rows: List[Dict[str, Any]] = field(default_factory=list)
+    capture_limit: int = 10_000
+
+    def record(self, row: Dict[str, Any]) -> None:
+        if len(self.rows) < self.capture_limit:
+            self.rows.append(dict(row))
+
+    def record_transition(
+        self,
+        *,
+        transition: KernelTransition,
+        slot: TradeSlot,
+        event: Optional[VenueEvent] = None,
+        control: Optional[KernelControlSnapshot] = None,
+    ) -> None:
+        row = _transition_row(transition=transition, slot=slot, event=event, control=control)
+        self.record(row)
+
+
+class ClickHouseKernelJournal:
+    """Fire-and-forget ClickHouse journal.
+
+    The sink is a small callable of the form ``sink(table_name, row_dict)``.
+    """
+
+    def __init__(self, sink: Optional[JournalSink] = None):
+        self.sink = sink
+
+    def record(self, row: Dict[str, Any]) -> None:
+        if self.sink is not None:
+            self.sink("dita_kernel_debug", row)
+
+    def record_transition(
+        self,
+        *,
+        transition: KernelTransition,
+        slot: TradeSlot,
+        event: Optional[VenueEvent] = None,
+        control: Optional[KernelControlSnapshot] = None,
+    ) -> None:
+        self.record(_transition_row(transition=transition, slot=slot, event=event, control=control))
+
+
+def _transition_row(
+    *,
+    transition: KernelTransition,
+    slot: TradeSlot,
+    event: Optional[VenueEvent],
+    control: Optional[KernelControlSnapshot],
+) -> Dict[str, Any]:
+    return {
+        "ts": transition.timestamp.isoformat() if hasattr(transition.timestamp, "isoformat") else str(transition.timestamp),
+        "trade_id": transition.trade_id,
+        "slot_id": transition.slot_id,
+        "prev_state": transition.prev_state.value,
+        "next_state": transition.next_state.value,
+        "trigger": transition.trigger,
+        "intent_id": transition.intent_id,
+        "event_id": transition.event_id,
+        "control_mode": transition.control_mode,
+        "control_verbosity": transition.control_verbosity,
+        "slot_state": slot.to_dict(),
+        "event_payload": json_safe(event) if event is not None else {},
+        "control_snapshot": control.as_dict() if control is not None else {},
+        "slot_state_json": json_text(slot.to_dict()),
+    }