feat: System update and direnv fixes

- Updated flake.lock to latest NixOS 25.05 packages (2025-06-04)
- Fixed direnv functionality across system configuration
- Added direnv and nix-direnv packages to base.nix
- Integrated direnv shell hook in zsh configuration
- Enhanced user management with geir.nix updates
- Added comprehensive package lists and development tools
- Successfully tested NixOS configuration rebuild
- System ready for reboot with latest updates

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1748889542,
-        "narHash": "sha256-Hb4iMhIbjX45GcrgOp3b8xnyli+ysRPqAgZ/LZgyT5k=",
+        "lastModified": 1749024892,
+        "narHash": "sha256-OGcDEz60TXQC+gVz5sdtgGJdKVYr6rwdzQKuZAJQpCA=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "10d7f8d34e5eb9c0f9a0485186c1ca691d2c5922",
+        "rev": "8f1b52b04f2cb6e5ead50bd28d76528a2f0380ef",
         "type": "github"
       },
       "original": {