fix: make SEC quality gating terminal-safe

app/models/sec_filing_gap.py

@@ -10,8 +10,8 @@ class SecFilingGap(Base):
     """Active SEC filing that could not yet be reconstructed.
 
     Rows form a small retry queue. Successful snapshot ingestion deletes the
-    matching row; while a row remains, tickers mapped to its CIK are not eligible
-    for actionable trade setups.
+    matching row; a later valid filing supersedes it. While a current row remains,
+    tickers mapped to its CIK are not eligible for actionable trade setups.
     """
 
     __tablename__ = "sec_filing_gaps"
@@ -29,3 +29,4 @@ class SecFilingGap(Base):
     coregistrant_ciks_json: Mapped[str | None] = mapped_column(Text, nullable=True)
     first_seen_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
     last_attempted_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    escalated_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)