feat(api): real klines/trades from indexer + auto table creation

- charts.py: serve OHLCV bars & trades from Postgres (klines/trades tables written by indexer), no synthetic data
- entities.py: add TradeModel/KlineModel matching indexer schema
- main.py: idempotent create_all on startup
- config.py: unify default DATABASE_URL with docker-compose/indexer

app/models/entities.py

@@ -118,3 +118,38 @@ class OrderModel(Base):
     fee = Column(Numeric(precision=36, scale=18), default=Decimal("0"), nullable=False)
     tx_hash = Column(String(66), nullable=True)
     created_at = Column(DateTime, default=datetime.utcnow, nullable=False)
+
+class TradeModel(Base):
+    """链上真实成交明细 (由 Indexer 确定性投影写入)"""
+    __tablename__ = "trades"
+
+    id = Column(BigInteger().with_variant(Integer, "sqlite"), primary_key=True, autoincrement=True)
+    tx_hash = Column(String(66), nullable=True, index=True)
+    market_address = Column(String(42), nullable=False, index=True)
+    outcome_index = Column(BigInteger, nullable=False)
+    trade_type = Column(String(8), nullable=False) # "MINT" | "REDEEM"
+    price = Column(Numeric(precision=36, scale=18), nullable=False)
+    volume = Column(Numeric(precision=36, scale=18), nullable=False)
+    block_number = Column(BigInteger, nullable=True)
+    ts = Column(BigInteger, nullable=True, index=True)
+
+    __table_args__ = (
+        Index("idx_trades_market_ts", "market_address", "outcome_index", "ts"),
+    )
+
+class KlineModel(Base):
+    """秒级 OHLCV K 线 (由 Indexer 按 5 秒窗口确定性聚合写入)"""
+    __tablename__ = "klines"
+
+    market_address = Column(String(42), primary_key=True)
+    outcome_index = Column(BigInteger, primary_key=True)
+    bar_time = Column(BigInteger, primary_key=True)
+    open = Column(Numeric(precision=36, scale=18), nullable=False)
+    high = Column(Numeric(precision=36, scale=18), nullable=False)
+    low = Column(Numeric(precision=36, scale=18), nullable=False)
+    close = Column(Numeric(precision=36, scale=18), nullable=False)
+    volume = Column(Numeric(precision=36, scale=18), nullable=False)
+
+    __table_args__ = (
+        Index("idx_klines_market_time", "market_address", "outcome_index", "bar_time"),
+    )