feat(kevin): SA models for bridge audit + backtest persistence

3 tables (kevin_signal_bridge_state, kevin_backtest_runs,
kevin_backtest_trades) all UUID-keyed for consistency with Trade/Position.
KEVIN_STRATEGY_UUID constant pinned for FK joins from Trade.strategy_id.

shared/models/__init__.py

@@ -23,6 +23,14 @@ from shared.models.meet_kevin import (
     KevinAnalysis,
     KevinStockMention,
 )
+from shared.models.meet_kevin_trading import (
+    BridgeStatus,
+    KevinBacktestRun,
+    KevinBacktestRunStatus,
+    KevinBacktestTrade,
+    KevinSignalBridgeState,
+    TriggerSource,
+)
 
 __all__ = [
     "Base",
@@ -57,4 +65,11 @@ __all__ = [
     "KevinTranscript",
     "KevinAnalysis",
     "KevinStockMention",
+    # Meet Kevin trading
+    "BridgeStatus",
+    "KevinBacktestRun",
+    "KevinBacktestRunStatus",
+    "KevinBacktestTrade",
+    "KevinSignalBridgeState",
+    "TriggerSource",
 ]

shared/models/meet_kevin_trading.py

@@ -0,0 +1,171 @@
+"""Tables added in v2 for paper-trading + backtest persistence.
+
+  - KevinSignalBridgeState  audit trail: one row per processed mention
+  - KevinBacktestRun        one row per backtest invocation
+  - KevinBacktestTrade      per-trade detail within a run
+"""
+
+from __future__ import annotations
+
+import enum
+import uuid
+from datetime import datetime
+from decimal import Decimal
+from typing import Any
+
+from sqlalchemy import (
+    BigInteger,
+    DateTime,
+    Enum as SAEnum,
+    ForeignKey,
+    Index,
+    Integer,
+    Numeric,
+    String,
+    Text,
+    func,
+)
+from sqlalchemy.dialects.postgresql import JSONB, UUID
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from shared.models.base import Base, TimestampMixin
+
+
+class BridgeStatus(str, enum.Enum):
+    EMITTED = "emitted"
+    SKIPPED_NON_TRADABLE = "skipped_non_tradable"
+    SKIPPED_BLOCKLIST = "skipped_blocklist"
+    SKIPPED_CAPS = "skipped_caps"
+    DEFERRED = "deferred"
+    BROKER_REJECTED = "broker_rejected"
+    DRY_RUN = "dry_run"  # kill-switch off
+
+
+class KevinBacktestRunStatus(str, enum.Enum):
+    RUNNING = "running"
+    COMPLETED = "completed"
+    FAILED = "failed"
+
+
+class TriggerSource(str, enum.Enum):
+    MANUAL = "manual"
+    SCHEDULED = "scheduled"
+
+
+class KevinSignalBridgeState(TimestampMixin, Base):
+    __tablename__ = "kevin_signal_bridge_state"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
+    )
+    mention_id: Mapped[int] = mapped_column(
+        BigInteger,
+        ForeignKey("kevin_stock_mentions.id"),
+        nullable=False,
+        unique=True,
+    )
+    bridge_status: Mapped[BridgeStatus] = mapped_column(
+        SAEnum(
+            BridgeStatus,
+            name="kevin_bridge_status",
+            values_callable=lambda x: [e.value for e in x],
+        ),
+        nullable=False,
+    )
+    signal_id: Mapped[uuid.UUID | None] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("signals.id"), nullable=True
+    )
+    trade_id: Mapped[uuid.UUID | None] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("trades.id"), nullable=True
+    )
+    effective_conviction: Mapped[Decimal | None] = mapped_column(
+        Numeric(4, 3), nullable=True
+    )
+    decided_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+    notes: Mapped[str | None] = mapped_column(Text, nullable=True)
+
+    __table_args__ = (
+        Index("ix_bridge_state_status_decided", "bridge_status", "decided_at"),
+    )
+
+
+class KevinBacktestRun(TimestampMixin, Base):
+    __tablename__ = "kevin_backtest_runs"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
+    )
+    run_uuid: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), unique=True, nullable=False, default=uuid.uuid4
+    )
+    started_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+    finished_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
+    status: Mapped[KevinBacktestRunStatus] = mapped_column(
+        SAEnum(
+            KevinBacktestRunStatus,
+            name="kevin_backtest_run_status",
+            values_callable=lambda x: [e.value for e in x],
+        ),
+        nullable=False,
+    )
+    trigger_source: Mapped[TriggerSource] = mapped_column(
+        SAEnum(
+            TriggerSource,
+            name="kevin_backtest_trigger_source",
+            values_callable=lambda x: [e.value for e in x],
+        ),
+        nullable=False,
+        default=TriggerSource.MANUAL,
+    )
+    params_json: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False)
+    metrics_json: Mapped[dict[str, Any] | None] = mapped_column(JSONB, nullable=True)
+    equity_curve_json: Mapped[list[Any] | None] = mapped_column(JSONB, nullable=True)
+    benchmark_curve_json: Mapped[list[Any] | None] = mapped_column(JSONB, nullable=True)
+    error_message: Mapped[str | None] = mapped_column(Text, nullable=True)
+
+    trades: Mapped[list["KevinBacktestTrade"]] = relationship(
+        back_populates="run", cascade="all, delete-orphan"
+    )
+
+    __table_args__ = (
+        Index("ix_backtest_runs_started", "started_at"),
+        Index("ix_backtest_runs_status_started", "status", "started_at"),
+    )
+
+
+class KevinBacktestTrade(TimestampMixin, Base):
+    __tablename__ = "kevin_backtest_trades"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
+    )
+    run_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("kevin_backtest_runs.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    symbol: Mapped[str] = mapped_column(String(16), nullable=False)
+    source_mention_id: Mapped[int | None] = mapped_column(
+        BigInteger, ForeignKey("kevin_stock_mentions.id"), nullable=True
+    )
+    entry_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    entry_price: Mapped[Decimal] = mapped_column(Numeric(12, 4), nullable=False)
+    exit_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    exit_price: Mapped[Decimal | None] = mapped_column(Numeric(12, 4))
+    qty: Mapped[Decimal] = mapped_column(Numeric(14, 4), nullable=False)
+    pnl_usd: Mapped[Decimal | None] = mapped_column(Numeric(14, 4))
+    pnl_pct: Mapped[Decimal | None] = mapped_column(Numeric(8, 4))
+    holding_days_actual: Mapped[int | None] = mapped_column(Integer)
+
+    run: Mapped["KevinBacktestRun"] = relationship(back_populates="trades")
+
+    __table_args__ = (
+        Index("ix_backtest_trades_run_symbol", "run_id", "symbol"),
+        Index("ix_backtest_trades_run_entry", "run_id", "entry_at"),
+    )