feat(scouts): add ScoutTriageQueue table + cloud_scout_configs gmail fields

Tasks 12+13 of Phase 2 — first new infra after rename.
Alembic 008 creates scout_triage_queue with unique constraint on
(scout_id, source_msg_ref) and partial index on expires_at for active
rows. Adds four columns to cloud_scout_configs: auto_trash_spam,
gmail_history_id, gmail_watch_expires_at, device_inactivity_pause_days.
SQLAlchemy model ScoutTriageQueue added; CloudScoutConfig updated to
match. Imports extended with UniqueConstraint and text.

app/models.py

@@ -34,8 +34,10 @@ from sqlalchemy import (
     LargeBinary,
     String,
     Text,
+    UniqueConstraint,
     Uuid,
     func,
+    text,
 )
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
@@ -217,6 +219,10 @@ class CloudScoutConfig(Base):
     updated_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
     )
+    auto_trash_spam: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False, server_default=text("false"))
+    gmail_history_id: Mapped[str | None] = mapped_column(String(64), nullable=True)
+    gmail_watch_expires_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    device_inactivity_pause_days: Mapped[int] = mapped_column(Integer, nullable=False, default=14, server_default="14")
 
     run_logs: Mapped[list["ScoutRunLog"]] = relationship(
         back_populates="cloud_scout",
@@ -227,6 +233,26 @@ class CloudScoutConfig(Base):
     )
 
 
+class ScoutTriageQueue(Base):
+    __tablename__ = "scout_triage_queue"
+    __table_args__ = (
+        UniqueConstraint("scout_id", "source_msg_ref", name="uq_scout_triage_queue_scout_msg"),
+    )
+
+    id: Mapped[str] = mapped_column(Uuid(as_uuid=False), primary_key=True, default=_uuid)
+    user_id: Mapped[str] = mapped_column(Uuid(as_uuid=False), ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
+    scout_id: Mapped[str] = mapped_column(Uuid(as_uuid=False), ForeignKey("cloud_scout_configs.id", ondelete="CASCADE"), nullable=False)
+    source_type: Mapped[str] = mapped_column(String(50), nullable=False)
+    source_msg_ref: Mapped[str] = mapped_column(String(255), nullable=False)
+    triage_verdict: Mapped[str] = mapped_column(String(20), nullable=False)
+    triage_reason: Mapped[str | None] = mapped_column(Text, nullable=True)
+    status: Mapped[str] = mapped_column(String(20), nullable=False, default="queued", server_default="queued")
+    triaged_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
+    delivered_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    acked_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+
+
 class ScoutRunLog(Base):
     __tablename__ = "scout_run_logs"