Rename package directories to match t3code outputs

- Move server and desktop Nix packages under `packages/t3code-*`
- Update flake outputs and README references to the new names

flake.nix

@@ -3,10 +3,8 @@
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
-    t3code = {
-      url = "github:pingdotgg/t3code";
-      flake = false;
-    };
+    t3code.url = "github:pingdotgg/t3code";
+    t3code.flake = false;
   };
 
   outputs = {
@@ -27,30 +25,30 @@
     packages = forAllSystems (
       system: let
         pkgs = import nixpkgs {inherit system;};
-        t3code-server = pkgs.callPackage ./packages/server {src = t3code;};
-        t3code-desktop = pkgs.callPackage ./packages/desktop {src = t3code;};
+        t3code-desktop = pkgs.callPackage ./packages/t3code-desktop {src = t3code;};
+        t3code-server = pkgs.callPackage ./packages/t3code-server {src = t3code;};
       in {
-        inherit t3code-server t3code-desktop;
+        inherit t3code-desktop t3code-server;
         default = t3code-desktop;
       }
     );
 
     apps = forAllSystems (system: rec {
-      t3code-server = {
-        type = "app";
-        program = lib.getExe self.packages.${system}.t3code-server;
-      };
       t3code-desktop = {
         type = "app";
         program = lib.getExe self.packages.${system}.t3code-desktop;
       };
+      t3code-server = {
+        type = "app";
+        program = lib.getExe self.packages.${system}.t3code-server;
+      };
       default = t3code-desktop;
     });
 
     checks = forAllSystems (
       system: {
-        t3code-server = self.packages.${system}.t3code-server;
         t3code-desktop = self.packages.${system}.t3code-desktop;
+        t3code-server = self.packages.${system}.t3code-server;
       }
     );
   };