Add *arr media stack + Gitea to jupiter

- sabnzbd, prowlarr, sonarr, radarr, clonarr, seerr, cinephage, mediamanager
  services, wired into jupiter with LAN Caddy vhosts.
- Gitea: migrated the old ZimaOS docker instance's data (sqlite db, 4 repos,
  no LFS objects) into the NixOS module's default stateDir layout. HTTP via
  Caddy; git SSH on its own built-in server at :2222 (not :222 - the unpriv
  gitea user can't bind <1024).
- mediamanager-nix flake input for the mediamanager service.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

flake.nix

@@ -15,9 +15,13 @@
       url = "github:nix-community/nixos-images";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+    mediamanager-nix = {
+      url = "github:strangeglyph/mediamanager-nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
-  outputs = { self, nixpkgs, disko, sops-nix, nixos-images, ... }@inputs:
+  outputs = { self, nixpkgs, disko, sops-nix, nixos-images, mediamanager-nix, ... }@inputs:
     let
       system = "x86_64-linux";
     in