feat: Problems API, ingest hook, and UI

backend/app/models/problem.py

@@ -0,0 +1,35 @@
+from datetime import datetime
+
+from sqlalchemy import DateTime, ForeignKey, String, Text, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+class Problem(Base):
+    __tablename__ = "problems"
+
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    host_id: Mapped[int | None] = mapped_column(ForeignKey("hosts.id"), index=True)
+    title: Mapped[str] = mapped_column(String(256))
+    summary: Mapped[str] = mapped_column(Text)
+    severity: Mapped[str] = mapped_column(String(16), index=True)
+    status: Mapped[str] = mapped_column(String(32), index=True, default="open")
+    rule_id: Mapped[str | None] = mapped_column(String(64))
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), onupdate=func.now()
+    )
+
+    host: Mapped["Host | None"] = relationship()
+    event_links: Mapped[list["ProblemEvent"]] = relationship(back_populates="problem")
+
+
+class ProblemEvent(Base):
+    __tablename__ = "problem_events"
+
+    problem_id: Mapped[int] = mapped_column(ForeignKey("problems.id", ondelete="CASCADE"), primary_key=True)
+    event_id: Mapped[int] = mapped_column(ForeignKey("events.id", ondelete="CASCADE"), primary_key=True)
+
+    problem: Mapped["Problem"] = relationship(back_populates="event_links")
+    event: Mapped["Event"] = relationship()