Update flake.lock revisions and add new wallpapers

Bump helium to 0.15.6.1 and update flake.lock revisions.
Add new wallpaper images.

flake.lock

@@ -181,11 +181,11 @@
       },
       "locked": {
         "dir": "pkgs/firefox-addons",
-        "lastModified": 1787025780,
-        "narHash": "sha256-NhyLP9G4DFOn/7aYr7K/D7hWrzEGr5EgUBV+lpdmJ24=",
+        "lastModified": 1787112172,
+        "narHash": "sha256-UMk1vXwGwx7dSxHAst6EcOvsryXIRuRF1QIFCz3oG+k=",
         "owner": "rycee",
         "repo": "nur-expressions",
-        "rev": "5ad360b6d3cb0aa1b61f9cb27fef113ca9117c37",
+        "rev": "b6890db16471fa96d9223b538bcd30af7ea0a9bb",
         "type": "gitlab"
       },
       "original": {
@@ -364,11 +364,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1786999651,
-        "narHash": "sha256-MTGMFlLDTklsXhCp4r5GXB4VAVadPdalXLvUjd/K7h0=",
+        "lastModified": 1787176219,
+        "narHash": "sha256-djoRr6jBpe35q/0JwAvXpFXg1Ktf+X54NU2RLR7wnHw=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "353742587cbaf079b3caee743115d037bc51fea6",
+        "rev": "c53d643b3737e2fcd04e6cb3b3580ef50b2087a0",
         "type": "github"
       },
       "original": {
@@ -437,11 +437,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1787001381,
-        "narHash": "sha256-Ue1Yo8gfHdD4TMtNewhA4tkSYeFqXThju0nCyJc3ALo=",
+        "lastModified": 1787135253,
+        "narHash": "sha256-RD2kNWCG+Bjo6h+JVjWVNntZs2GtRoeY2xHjts/FNkA=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "ec2d622de0773551768cf98f3fc50cbcc003b9c5",
+        "rev": "ffb3c9b700e759be2ef13237c9d8f953b32a1e46",
         "type": "github"
       },
       "original": {
@@ -489,11 +489,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1787066558,
-        "narHash": "sha256-nDiJkzVkxRmPQ/FRb8ZKDungVh88+Qzw5su6LXKC91M=",
+        "lastModified": 1787196493,
+        "narHash": "sha256-vlpv5X3qOzoTGtJxejXkIdivgnJ3jI+3Gn1neD6y/mI=",
         "owner": "noctalia-dev",
         "repo": "noctalia-shell",
-        "rev": "356a41a5cacd544730d40b936d2e66ed99e9995a",
+        "rev": "02286bbdcfa81dc3675c9de1d7203a466fcaf0eb",
         "type": "github"
       },
       "original": {
@@ -647,11 +647,11 @@
         "tinted-zed": "tinted-zed"
       },
       "locked": {
-        "lastModified": 1786531493,
-        "narHash": "sha256-F93yabBSW2TpxKYMcArQOnFuCqBgAdbfZsdl0w5Pojg=",
+        "lastModified": 1787175104,
+        "narHash": "sha256-tzNjlb0loxeWlipvxSNAUUihloeTZoyGFhEen87yM9k=",
         "owner": "danth",
         "repo": "stylix",
-        "rev": "1e6ccadeda179d96728b4a9f20fc9d4dcf6b6059",
+        "rev": "a9e5a76a1b75b137f266e4f445e1eaba82e9783e",
         "type": "github"
       },
       "original": {