Update flake.lock and vscode configuration

- Updated package references in flake.lock for various dependencies.
- Changed VSCode package from vscodium to vscode and updated extensions.
- Enabled SSH agent start in ssh.nix.
- Refined overlays in default.nix for better package management.

overlays/default.nix

@@ -15,29 +15,24 @@
   linuxModifications = final: prev: prev.lib.mkIf final.stdenv.isLinux {};
 
   modifications = final: prev: {
-    # example = prev.example.overrideAttrs (oldAttrs: let ... in {
-    # ...
-    # });
-    #    flameshot = prev.flameshot.overrideAttrs {
-    #      cmakeFlags = [
-    #        (prev.lib.cmakeBool "USE_WAYLAND_GRIM" true)
-    #        (prev.lib.cmakeBool "USE_WAYLAND_CLIPBOARD" true)
-    #      ];
-    #    };
     overlays = [
-      inputs.nix4vscode.overlays.forVscode
+      inputs.nix4vscode.overlays.default
+
       (self: super: {
-          vscodium =
-            super.vscodium.overrideAttrs (oldAttrs: rec {
-                nativeBuildInputs = oldAttrs.nativeBuildInputs or [] ++ [self.makeWrapper];
-                postInstall =
-                  oldAttrs.postInstall
-      or ""
-                  + ''
-                    wrapProgram $out/bin/codium --set LD_LIBRARY_PATH "${self.stdenv.cc.cc.lib}/lib/"
-                  '';
-              });
-        })
+        vscode = final.unstable.vscode;
+        vscodium = final.unstable.vscodium;
+      })
+
+      (self: super: {
+        vscodium = super.vscodium.overrideAttrs (oldAttrs: rec {
+          nativeBuildInputs = oldAttrs.nativeBuildInputs or [] ++ [self.makeWrapper];
+          postInstall =
+            (oldAttrs.postInstall or "")
+            + ''
+              wrapProgram $out/bin/codium --set LD_LIBRARY_PATH "${self.stdenv.cc.cc.lib}/lib/"
+            '';
+        });
+      })
     ];
   };