fix(packaging): unpack @img prebuilt sharp binaries so deb ships bundled libvips

build.asarUnpack only claimed node_modules/sharp/**, so electron-builder
pruned the @img/sharp-* optionalDependencies: the asar kept 34 pure-JS
@img entries while the bundled libvips shared libraries never shipped.
At boot sharp's loader fell back to a system-libvips-linked binding and
dlopen failed, crashing the main process. Claim the prebuilt packages
explicitly (@img/** and @napi-rs/**) per the sharp+electron-builder
recipe, and guard the built output with a packaging regression test.

Amit Haridas

package.json

@@ -116,6 +116,8 @@
     "asarUnpack": [
       "node_modules/ffmpeg-static/**",
       "node_modules/sharp/**",
+      "node_modules/@img/**",
+      "node_modules/@napi-rs/**",
       "assets/fonts/**"
     ],
     "extraFiles": [],

tests/packaging-sharp.test.js

@@ -0,0 +1,62 @@
+const fs = require('fs');
+const path = require('path');
+
+// Regression guard for the deb startup crash (2026-08-23): the packaged build
+// pruned the @img/sharp-* native bindings (only the pure-JS @img/colour entries
+// landed in the asar), so sharp's loader fell back to a binding that links
+// against system libvips and the main process died on ERR_DLOPEN_FAILED before
+// any window opened. When a linux build is present, the prebuilt sharp packages
+// — including the bundled libvips shared libraries — must be unpacked next to
+// the asar (build.asarUnpack claims node_modules/@img/** and node_modules/@napi-rs/**).
+const UNPACKED_IMG_DIR = path.join(
+  __dirname,
+  '..',
+  'dist',
+  'linux-unpacked',
+  'resources',
+  'app.asar.unpacked',
+  'node_modules',
+  '@img'
+);
+
+const buildOutputExists = fs.existsSync(UNPACKED_IMG_DIR);
+
+function listFilesRecursively(dir) {
+  const files = [];
+  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
+    const full = path.join(dir, entry.name);
+    if (entry.isDirectory()) {
+      files.push(...listFilesRecursively(full));
+    } else {
+      files.push(full);
+    }
+  }
+  return files;
+}
+
+(buildOutputExists ? describe : describe.skip)('packaged @img sharp prebuilt binaries', () => {
+  test('unpacked @img directory exists and is non-empty', () => {
+    const entries = fs.readdirSync(UNPACKED_IMG_DIR);
+    expect(entries.length).toBeGreaterThan(0);
+  });
+
+  test.each(['sharp-linux-x64', 'sharp-libvips-linux-x64'])(
+    '%s package is unpacked with contents',
+    (pkg) => {
+      const pkgDir = path.join(UNPACKED_IMG_DIR, pkg);
+      expect(fs.existsSync(pkgDir)).toBe(true);
+      expect(listFilesRecursively(pkgDir).length).toBeGreaterThan(0);
+    }
+  );
+
+  test('sharp-linux-x64 ships its native binding', () => {
+    const binding = path.join(UNPACKED_IMG_DIR, 'sharp-linux-x64', 'lib', 'sharp-linux-x64.node');
+    expect(fs.existsSync(binding)).toBe(true);
+  });
+
+  test('sharp-libvips-linux-x64 ships the bundled libvips shared libraries', () => {
+    const libvipsLibDir = path.join(UNPACKED_IMG_DIR, 'sharp-libvips-linux-x64', 'lib');
+    const sharedLibs = fs.readdirSync(libvipsLibDir).filter((f) => /^libvips.*\.so/.test(f));
+    expect(sharedLibs.length).toBeGreaterThan(0);
+  });
+});