Format trade prices to 3 decimals and round on ingest.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/factory.py

@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 from __future__ import annotations
 
+from typing import Any
+
 from flask import Flask
 
 from app.config import Config
@@ -8,11 +10,33 @@ from app.db import init_db, seed_if_empty
 from app.routes import register_routes
 
 
+def _fmt_price(value: Any, digits: int = 3) -> str:
+    """价格展示：固定小数位，避免浮点尾巴。"""
+    if value is None or value == "":
+        return "—"
+    try:
+        return f"{float(value):.{int(digits)}f}"
+    except (TypeError, ValueError):
+        return str(value)
+
+
+def _fmt_money(value: Any, digits: int = 2) -> str:
+    if value is None or value == "":
+        return "—"
+    try:
+        return f"{float(value):.{int(digits)}f}"
+    except (TypeError, ValueError):
+        return str(value)
+
+
 def create_app() -> Flask:
     app = Flask(__name__, template_folder="templates", static_folder="static")
     app.config.from_object(Config)
     app.secret_key = Config.SECRET_KEY
 
+    app.jinja_env.filters["fmt_price"] = _fmt_price
+    app.jinja_env.filters["fmt_money"] = _fmt_money
+
     init_db()
     seed_if_empty()
     register_routes(app)