Fix global version handling and unify app version across backend/frontend

backend/app/__init__.py

@@ -1 +1,50 @@
-"""BanGUI backend application package."""
+"""BanGUI backend application package.
+
+This package exposes the application version based on the project metadata.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Final
+
+import importlib.metadata
+import tomllib
+
+PACKAGE_NAME: Final[str] = "bangui-backend"
+
+
+def _read_pyproject_version() -> str:
+    """Read the project version from ``pyproject.toml``.
+
+    This is used as a fallback when the package metadata is not available (e.g.
+    when running directly from a source checkout without installing the package).
+    """
+
+    project_root = Path(__file__).resolve().parents[1]
+    pyproject_path = project_root / "pyproject.toml"
+    if not pyproject_path.exists():
+        raise FileNotFoundError(f"pyproject.toml not found at {pyproject_path}")
+
+    data = tomllib.loads(pyproject_path.read_text(encoding="utf-8"))
+    return str(data["project"]["version"])
+
+
+def _read_version() -> str:
+    """Return the current package version.
+
+    Prefer the project metadata in ``pyproject.toml`` when available, since this
+    is the single source of truth for local development and is kept in sync with
+    the frontend and Docker release version.
+
+    When running from an installed distribution where the ``pyproject.toml``
+    is not available, fall back to installed package metadata.
+    """
+
+    try:
+        return _read_pyproject_version()
+    except FileNotFoundError:
+        return importlib.metadata.version(PACKAGE_NAME)
+
+
+__version__ = _read_version()

backend/app/main.py

@@ -31,6 +31,7 @@ from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse, RedirectResponse
 from starlette.middleware.base import BaseHTTPMiddleware
 
+from app import __version__
 from app.config import Settings, get_settings
 from app.db import init_db
 from app.routers import (
@@ -365,7 +366,7 @@ def create_app(settings: Settings | None = None) -> FastAPI:
     app: FastAPI = FastAPI(
         title="BanGUI",
         description="Web interface for monitoring, managing, and configuring fail2ban.",
-        version="0.1.0",
+        version=__version__,
         lifespan=_lifespan,
     )