fix: patch sixel upng.js missing var declaration for bundled ESM

sixel/upng.js uses `module.exports = UPNG = {}` without declaring UPNG,
which becomes a ReferenceError in ESM strict mode when bun bundles it.
Fix via bun patch to add var declaration.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

bun.lock

@@ -125,6 +125,9 @@
       "version": "1.0.0",
     },
   },
+  "patchedDependencies": {
+    "sixel@0.16.0": "patches/sixel@0.16.0.patch",
+  },
   "packages": {
     "@alcalzone/ansi-tokenize": ["@alcalzone/ansi-tokenize@0.3.0", "", { "dependencies": { "ansi-styles": "^6.2.1", "is-fullwidth-code-point": "^5.0.0" } }, "sha512-p+CMKJ93HFmLkjXKlXiVGlMQEuRb6H0MokBSwUsX+S6BRX8eV5naFZpQJFfJHjRZY0Hmnqy1/r6UWl3x+19zYA=="],
 

package.json

@@ -135,5 +135,8 @@
   "devDependencies": {
     "@types/bun": "^1.3.11",
     "typescript": "^6.0.2"
+  },
+  "patchedDependencies": {
+    "sixel@0.16.0": "patches/sixel@0.16.0.patch"
   }
 }

patches/sixel@0.16.0.patch

@@ -0,0 +1,13 @@
+diff --git a/upng.js b/upng.js
+index 339e821ea5acdd0869f0915d72828a62f1520a83..15c1a3d3da2d99aece0807a5375971fe45829d4e 100644
+--- a/upng.js
++++ b/upng.js
+@@ -4,7 +4,7 @@
+  * commit cb463cb7b857fc1fbd47bb8628c536e02aaa24ce
+  * license: MIT License, Copyright (c) 2017 Photopea
+  */
+-module.exports = UPNG = {};
++var UPNG = {}; module.exports = UPNG;
+ 
+ 	
+