feat(submit): P1-03 BROKER_ACK_ALLOWED_FIELDS 6필드 추가

submit.py 의 broker_ack sanitize 화이트리스트를 9필드에서 15필드로 확장.
신규: broker_order_id, order_no, order_date, is_reserved (P0-02 capture
시 토스 broker create 응답 필드), http_status (P1-01 응답 status_code),
guard_reason (P1-01 OFF 분기 final_submit_guard_reason).

단위 테스트 2건 추가: 신규 6필드 sanitize 보존 검증 (test 데이터는
P0-02 SCHD capture 응답 그대로 — orderId="V56qyv7r", orderNo=3,
orderDate="2026-05-04") + OFF 분기 guard_reason 보존 검증.

전체 23 tests PASS (기존 forbidden field drop 동작 무영향).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: heeho

src/toss_browser_bridge/submit.py

@@ -45,6 +45,12 @@
     "quantity",
     "order_type",
     "ordered_at",
+    "broker_order_id",
+    "order_no",
+    "order_date",
+    "is_reserved",
+    "http_status",
+    "guard_reason",
 }
 VERIFY_SNAPSHOT_ALLOWED_FIELDS = {
     "status",

tests/test_submit_contract.py

@@ -178,6 +178,74 @@ def test_mutation_journal_sanitizes_forbidden_fields(tmp_path) -> None:
     assert saved == sanitize_mutation_journal_entry(entry)
 
 
+def test_mutation_journal_preserves_broker_create_fields(tmp_path) -> None:
+    path = tmp_path / "mutation-journal.jsonl"
+    entry = append_mutation_journal(
+        path,
+        {
+            "mutation_id": "mut_5678",
+            "kind": "place_order",
+            "requested_at": "2026-05-04T23:40:49+09:00",
+            "preview_fingerprint": "sha256:create",
+            "confirm_phrase_hash": "sha256:phrase",
+            "submit_state": "submitted",
+            "verification_state": "pending",
+            "broker_ack": {
+                "status": "submitted",
+                "code": "OK",
+                "message": "SCHD 판매 주문 완료",
+                "market": "us",
+                "symbol": "SCHD",
+                "side": "sell",
+                "quantity": 1,
+                "order_type": "limit",
+                "ordered_at": "2026-05-04T23:40:49+09:00",
+                "broker_order_id": "V56qyv7r",
+                "order_no": 3,
+                "order_date": "2026-05-04",
+                "is_reserved": False,
+                "http_status": 200,
+            },
+        },
+    )
+
+    ack = entry["broker_ack"]
+    assert ack["broker_order_id"] == "V56qyv7r"
+    assert ack["order_no"] == 3
+    assert ack["order_date"] == "2026-05-04"
+    assert ack["is_reserved"] is False
+    assert ack["http_status"] == 200
+
+
+def test_mutation_journal_preserves_guard_reason_on_blocked_entry(tmp_path) -> None:
+    path = tmp_path / "mutation-journal.jsonl"
+    entry = append_mutation_journal(
+        path,
+        {
+            "mutation_id": "mut_blocked",
+            "kind": "place_order",
+            "requested_at": "2026-05-05T10:00:00+09:00",
+            "preview_fingerprint": "sha256:blocked",
+            "confirm_phrase_hash": "sha256:phrase",
+            "submit_state": "submit_blocked",
+            "verification_state": "pending",
+            "broker_ack": {
+                "status": "prepared",
+                "code": "PREPARED",
+                "message": "prepare preflight succeeded",
+                "guard_reason": "disabled_by_default",
+                "market": "us",
+                "symbol": "AAPL",
+                "side": "buy",
+                "quantity": 1,
+                "order_type": "limit",
+            },
+        },
+    )
+
+    assert entry["broker_ack"]["guard_reason"] == "disabled_by_default"
+
+
 def test_mutation_journal_line_preview_is_sanitized() -> None:
     line = mutation_journal_line_preview(
         {