feat(config): add startup_timeout option with context propagation (#739)

docs/documentation/configuration/overview.md

@@ -45,6 +45,7 @@ advanced:
   route_table_offset: 20000
   api_admin_only: true
   limit_additional_user_peers: 0
+  startup_timeout: 5m
 
 database:
   debug: false
@@ -363,6 +364,12 @@ Additional or more specialized configuration options for logging and interface c
 - **Environment Variable:** `WG_PORTAL_ADVANCED_LIMIT_ADDITIONAL_USER_PEERS`
 - **Description:** Limit additional peers a normal user can create. `0` means unlimited.
 
+### `startup_timeout`
+- **Default:** `5m`
+- **Environment Variable:** `WG_PORTAL_ADVANCED_STARTUP_TIMEOUT`
+- **Description:** Timeout for the application startup process. 
+  Increase this value if you are using a MikroTik backend with many clients.
+
 ---
 
 ## Database