chore: update flake inputs and adjust configs

- Update flake inputs (home-manager, HyprPanel, nixpkgs variants, NUR, AGENTS)
- Switch OpenCode agents to opencode/ model provider
- Remove webcord package from media config
- Fix thunar plugins namespace (xfce.* → pkgs.*)
- Upgrade m3-kratos kernel to 6.18
- Disable ADB and qdrant service on m3-kratos
- Enable qdrant overlay using stable nixpkgs

hosts/m3-kratos/services/default.nix

@@ -15,7 +15,7 @@
     gvfs.enable = true;
     trezord.enable = true;
     gnome.gnome-keyring.enable = true;
-    qdrant.enable = true;
+    qdrant.enable = false;
     stirling-pdf.enable = true;
     avahi = {
       enable = true;