Update default API token expiration to 50 years

- Change default token expiration from 1 year (365 days) to 50 years (365*50 days)
- This provides long-term API access for external applications
- Tokens created with the new default will expire in approximately 2074
- Custom expiration periods can still be specified when creating tokens

app/models.py

@@ -50,9 +50,9 @@ class User(UserMixin, db.Model):
         # Generate a secure random token
         token_value = secrets.token_urlsafe(32)
         
-        # Set expiration (default to 1 year if not specified)
+        # Set expiration (default to 50 years if not specified)
         if expires_in is None:
-            expires_at = datetime.utcnow() + timedelta(days=365)
+            expires_at = datetime.utcnow() + timedelta(days=365*50)  # 50 years
         else:
             expires_at = datetime.utcnow() + expires_in