chore: upgrade all 14 plugins, fix config-diff key, pin netbox base image

- plugin_requirements.txt: pinned ==versions (10 plugins updated vs PyPI)
- Dockerfile-Plugins: FROM netbox:latest -> netbox:v4.6-5.0.2 (reproducible)
- configuration/plugins.py: fix netbox-config-diff -> netbox_config_diff key (required_settings USERNAME/PASSWORD)
- docker-compose.yml: VERSION default v4.6-5.0.1 -> v4.6-5.0.2
- README-NETBOX-MCP.md: fix NetBox version 6.0.4 -> 4.6.10, mark plugins TODO done
- NetBox 4.6.0 -> 4.6.10; all 14 plugins now load (config_diff, secrets, qrcode, floorplan revived)
NOTE: docker-compose.override.yml (housekeeping DB env fix) is gitignored - kept local

configuration/plugins.py

@@ -153,9 +153,10 @@ PLUGINS_CONFIG = {
     "netbox-data-flows": {
 #   https://github.com/Alef-Burzmali/netbox-data-flows/
     },
-    "netbox-config-diff": {
+    "netbox_config_diff": {
 #   https://github.com/miaow2/netbox-config-diff
         #define credentials for devices connection:
+        # Новая версия (2.15+) требует эти поля обязательно — см. required_settings в __init__.py
         "USERNAME": "foo",
         "PASSWORD": "bar",
         "AUTH_SECONDARY": "foobar",  # define here password for accessing Privileged EXEC mode, this variable is optional