Add VERSION file and live version display on settings page

- New VERSION file at project root, starting at 0.3.0.
- config.py reads VERSION and exposes it as Config.VERSION.
- Admin settings page now renders the live version from config.
- Semantic versioning convention: MAJOR for breaking/user-facing changes,
  MINOR for new features, PATCH for bug fixes and small polish.

config.py

@@ -32,10 +32,20 @@ Environment variables (defaults shown):
 import os
 from dotenv import load_dotenv
 
+from pathlib import Path
+
 # Load variables from .env file if present (development mode).
 load_dotenv()
 
 
+def _load_version():
+    """Read the package version from the VERSION file next to this module."""
+    version_file = Path(__file__).parent / 'VERSION'
+    if version_file.exists():
+        return version_file.read_text().strip()
+    return '0.0.0'
+
+
 class Config:
     # Flask secret key: used to sign session cookies and encrypt stored credentials.
     SECRET_KEY = os.environ.get('APP_SECRET_KEY', 'dev-secret-change-me')
@@ -82,3 +92,6 @@ class Config:
     # Informational price shown to the operator/customer; actual payment is collected manually (e.g. Square).
     PRICE_PER_VERSION = float(os.environ.get('PRICE_PER_VERSION', '10.00'))
     CURRENCY = os.environ.get('CURRENCY', 'CAD')
+
+    # Package version, read from VERSION file.
+    VERSION = _load_version()