Add mastodon default patches for yarn-4.14-support.patch

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/7fea5ede44b70af67136a82b41e39878cfb3a51b?narHash=sha256-adRHzYRN0huy51aAykoXC4xxBe84AupPMp81lmoNJHM%3D' (2026-04-30)
  → 'github:NixOS/nixpkgs/a3c34a1dd63140ab2150ebb4fa290bbbae58193b?narHash=sha256-wVKu7ZYV3ikh7RVDY1TVlaKwPTFvfkYnOzQGn3IqT4o%3D' (2026-05-15)
• Updated input 'nixpkgs-master':
    'github:NixOS/nixpkgs/6d457375d24d7d6c8b537a161660173ca225dfdf?narHash=sha256-/H8BBZdwWPVS9mzK5a8XskmLI%2BwMf6Zf8d22ZLeWSc4%3D' (2026-04-30)
  → 'github:NixOS/nixpkgs/b0415a300a8d2daf19019ef418f0b019ee38cf47?narHash=sha256-NZ9yg%2BVJy6RftGD3YXeqCEEVsPZH9hPu6yWm/bAuqLM%3D' (2026-05-15)
• Updated input 'nixpkgs-unstable':
    'github:NixOS/nixpkgs/417335fe04072fe234d9a566b72d7955df681844?narHash=sha256-XqqAel6imMLIA8ZeX5CNydzOaokD6GIoUf02DuFeWr4%3D' (2026-04-30)
  → 'github:NixOS/nixpkgs/758b562bc257084aef30b8e3efbdd61d292806c3?narHash=sha256-BxYhb8H0aVtiM1kGRt%2BS49NbsJMUMIHvOXxziE9u0nY%3D' (2026-05-15)

config/hosts/mastodon/mastodon.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs, nixpkgs-unstable, ... }:
 let
   tangerineUI = pkgs.fetchgit {
     url = "https://github.com/nileane/TangerineUI-for-Mastodon.git";
@@ -40,7 +40,7 @@ let
             modern-dark: styles/modern-dark.scss" >> $out/config/themes.yml
           '';
         };
-        patches = [
+        patches = prev.mastodon.src.patches ++ [
           "${mastodonNekoversePatches}/patches/001_increase_image_dimensions_limit.patch"
           "${mastodonNekoversePatches}/patches/002_disable_image_reprocessing.patch"
           "${mastodonNekoversePatches}/patches/003_make_toot_cute.patch"

config/hosts/mastodon/yarn.patch

@@ -0,0 +1,21 @@
+diff --git a/.yarnrc.yml b/.yarnrc.yml
+--- a/.yarnrc.yml
++++ b/.yarnrc.yml
+@@ -1 +1,6 @@
+ nodeLinker: node-modules
++
++approvedGitRepositories:
++  - "**"
++
++enableScripts: true
+diff --git a/yarn.lock b/yarn.lock
+--- a/yarn.lock
++++ b/yarn.lock
+@@ -2,6 +2,6 @@
+ # Manual changes might be lost - proceed with caution!
+ 
+ __metadata:
+-  version: 8
++  version: 9
+   cacheKey: 10c0
+ 

flake.lock

@@ -118,11 +118,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1777554940,
+        "lastModified": 1778830137,
-        "narHash": "sha256-adRHzYRN0huy51aAykoXC4xxBe84AupPMp81lmoNJHM=",
+        "narHash": "sha256-wVKu7ZYV3ikh7RVDY1TVlaKwPTFvfkYnOzQGn3IqT4o=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "7fea5ede44b70af67136a82b41e39878cfb3a51b",
+        "rev": "a3c34a1dd63140ab2150ebb4fa290bbbae58193b",
         "type": "github"
       },
       "original": {
@@ -134,11 +134,11 @@
     },
     "nixpkgs-master": {
       "locked": {
-        "lastModified": 1777592373,
+        "lastModified": 1778877216,
-        "narHash": "sha256-/H8BBZdwWPVS9mzK5a8XskmLI+wMf6Zf8d22ZLeWSc4=",
+        "narHash": "sha256-NZ9yg+VJy6RftGD3YXeqCEEVsPZH9hPu6yWm/bAuqLM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "6d457375d24d7d6c8b537a161660173ca225dfdf",
+        "rev": "b0415a300a8d2daf19019ef418f0b019ee38cf47",
         "type": "github"
       },
       "original": {
@@ -150,11 +150,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1777586718,
+        "lastModified": 1778843877,
-        "narHash": "sha256-XqqAel6imMLIA8ZeX5CNydzOaokD6GIoUf02DuFeWr4=",
+        "narHash": "sha256-BxYhb8H0aVtiM1kGRt+S49NbsJMUMIHvOXxziE9u0nY=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "417335fe04072fe234d9a566b72d7955df681844",
+        "rev": "758b562bc257084aef30b8e3efbdd61d292806c3",
         "type": "github"
       },
       "original": {