add paper trading: mark a setup as taken, track open P&L, sell

New paper_trades table (migration 007) + service/router. "Mark as taken" on each
setup card (shares prefilled from position sizing, entry from current price, both
editable) records a simulated trade. Overview gains an Open Trades table that
marks each position to the latest close — P&L in $, %, and R-multiples — with a
total unrealized P&L footer and a Sell button to close at the current price.
Closed trades are retained for future realized-P&L reporting.

Deploy: alembic upgrade (new paper_trades table).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/unit/test_paper_trade_service.py

@@ -0,0 +1,83 @@
+"""Tests for the paper-trading service."""
+
+from __future__ import annotations
+
+from datetime import date, datetime, timezone
+
+import pytest
+
+from app.exceptions import ValidationError
+from app.models.ohlcv import OHLCVRecord
+from app.models.ticker import Ticker
+from app.models.user import User
+from app.services import paper_trade_service as svc
+from tests.conftest import _test_session_factory  # type: ignore
+
+
+@pytest.fixture
+async def session():
+    async with _test_session_factory() as s:
+        yield s
+
+
+async def _seed(session, symbol: str, close: float) -> int:
+    user = await session.get(User, 1)
+    if user is None:
+        session.add(User(id=1, username="u", password_hash="x", role="user", has_access=True))
+        await session.flush()
+    t = Ticker(symbol=symbol)
+    session.add(t)
+    await session.flush()
+    session.add(OHLCVRecord(ticker_id=t.id, date=date.today(),
+                            open=close, high=close, low=close, close=close, volume=1))
+    await session.commit()
+    return t.id
+
+
+async def test_create_and_list_open(session):
+    await _seed(session, "AAA", close=110.0)
+    await svc.create_trade(session, 1, symbol="AAA", direction="long",
+                           entry_price=100.0, shares=10, stop_loss=95.0, target=120.0)
+    rows = await svc.list_trades(session, 1)
+    assert len(rows) == 1
+    row = rows[0]
+    assert row["symbol"] == "AAA"
+    assert row["status"] == "open"
+    assert row["current_price"] == 110.0  # marked to the latest close
+
+
+async def test_close_uses_current_price(session):
+    await _seed(session, "AAA", close=112.0)
+    trade = await svc.create_trade(session, 1, symbol="AAA", direction="long",
+                                   entry_price=100.0, shares=5, stop_loss=95.0, target=120.0)
+    closed = await svc.close_trade(session, 1, trade.id)
+    assert closed.status == "closed"
+    assert closed.close_price == 112.0
+    assert closed.closed_at is not None
+
+    rows = await svc.list_trades(session, 1, status="closed")
+    assert rows[0]["current_price"] == 112.0  # closed → realized exit
+
+
+async def test_close_with_explicit_price(session):
+    await _seed(session, "AAA", close=112.0)
+    trade = await svc.create_trade(session, 1, symbol="AAA", direction="short",
+                                   entry_price=100.0, shares=5, stop_loss=105.0, target=90.0)
+    closed = await svc.close_trade(session, 1, trade.id, close_price=93.0)
+    assert closed.close_price == 93.0
+
+
+async def test_invalid_direction_rejected(session):
+    await _seed(session, "AAA", close=100.0)
+    with pytest.raises(ValidationError):
+        await svc.create_trade(session, 1, symbol="AAA", direction="sideways",
+                               entry_price=100.0, shares=1, stop_loss=95.0, target=110.0)
+
+
+async def test_double_close_rejected(session):
+    await _seed(session, "AAA", close=100.0)
+    trade = await svc.create_trade(session, 1, symbol="AAA", direction="long",
+                                   entry_price=100.0, shares=1, stop_loss=95.0, target=110.0)
+    await svc.close_trade(session, 1, trade.id)
+    with pytest.raises(ValidationError):
+        await svc.close_trade(session, 1, trade.id)