feat(version): 显示应用版本号

app.py

@@ -25,6 +25,7 @@ import time
 import urllib.request
 from datetime import datetime
 from functools import wraps
+from pathlib import Path
 
 import pymysql
 
@@ -45,6 +46,16 @@ from reading_api import reading_bp
 # ======================================================================
 app = Flask(__name__, static_folder="static", template_folder="templates")
 
+try:
+    APP_VERSION = Path(__file__).with_name("VERSION").read_text(encoding="utf-8").strip()
+except FileNotFoundError:
+    APP_VERSION = "unknown"
+
+
+@app.context_processor
+def inject_app_version():
+    return {"app_version": APP_VERSION}
+
 # 注册当前看板数据接口，并保留旧客户端兼容路径。
 app.register_blueprint(reading_bp)
 register_auth(app)