build(frontend): serve pdf.js wasm decoders at /pdfjs-wasm/ via static-copy

pdf.js 5.x moved the JBIG2/CCITTFax/JPEG2000 image decoders into
WebAssembly. The wasm lives in node_modules and was never web-served, so
those decoders failed to initialise and CCITT (G4 fax) scans painted
blank in production while rendering fine in dev.

Add vite-plugin-static-copy (devDependency) to copy
node_modules/pdfjs-dist/wasm/* into build/client/pdfjs-wasm/, so the
assets are emitted into the SvelteKit client build and survive the
production Docker image — not just `npm run dev`. Verified that
`node build` serves /pdfjs-wasm/jbig2.wasm with 200 + application/wasm.

Refs #708

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/package-lock.json

@@ -54,6 +54,7 @@
 				"typescript-eslint": "^8.47.0",
 				"vite": "^7.3.3",
 				"vite-plugin-devtools-json": "^1.0.0",
+				"vite-plugin-static-copy": "^4.1.0",
 				"vitest": "^4.0.10",
 				"vitest-browser-svelte": "^2.0.1"
 			}
@@ -5078,6 +5079,33 @@
 				"url": "https://github.com/chalk/ansi-styles?sponsor=1"
 			}
 		},
+		"node_modules/anymatch": {
+			"version": "3.1.3",
+			"resolved": "https://registry.npmjs.org/anymatch/-/anymatch-3.1.3.tgz",
+			"integrity": "sha512-KMReFUr0B4t+D+OBkjR3KYqvocp2XaSzO55UcB6mgQMd3KbcE+mWTyvVV7D/zsdEbNnV6acZUutkiHQXvTr1Rw==",
+			"dev": true,
+			"license": "ISC",
+			"dependencies": {
+				"normalize-path": "^3.0.0",
+				"picomatch": "^2.0.4"
+			},
+			"engines": {
+				"node": ">= 8"
+			}
+		},
+		"node_modules/anymatch/node_modules/picomatch": {
+			"version": "2.3.2",
+			"resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.3.2.tgz",
+			"integrity": "sha512-V7+vQEJ06Z+c5tSye8S+nHUfI51xoXIXjHQ99cQtKUkQqqO1kO/KCJUfZXuB47h/YBlDhah2H3hdUGXn8ie0oA==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=8.6"
+			},
+			"funding": {
+				"url": "https://github.com/sponsors/jonschlinkert"
+			}
+		},
 		"node_modules/argparse": {
 			"version": "2.0.1",
 			"resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
@@ -5189,6 +5217,19 @@
 				"require-from-string": "^2.0.2"
 			}
 		},
+		"node_modules/binary-extensions": {
+			"version": "2.3.0",
+			"resolved": "https://registry.npmjs.org/binary-extensions/-/binary-extensions-2.3.0.tgz",
+			"integrity": "sha512-Ceh+7ox5qe7LJuLHoY0feh3pHuUDHAcRUeyL2VYghZwfpkNIy/+8Ocg0a3UuSoYzavmylwuLWQOf3hl0jjMMIw==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=8"
+			},
+			"funding": {
+				"url": "https://github.com/sponsors/sindresorhus"
+			}
+		},
 		"node_modules/brace-expansion": {
 			"version": "5.0.6",
 			"resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-5.0.6.tgz",
@@ -6723,6 +6764,19 @@
 				"url": "https://github.com/sponsors/sindresorhus"
 			}
 		},
+		"node_modules/is-binary-path": {
+			"version": "2.1.0",
+			"resolved": "https://registry.npmjs.org/is-binary-path/-/is-binary-path-2.1.0.tgz",
+			"integrity": "sha512-ZMERYes6pDydyuGidse7OsHxtbI7WVeUEozgR/g7rd0xUimYNlvZRE/K2MgZTjWy725IfelLeVcEM97mmtRGXw==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"binary-extensions": "^2.0.0"
+			},
+			"engines": {
+				"node": ">=8"
+			}
+		},
 		"node_modules/is-bun-module": {
 			"version": "2.0.0",
 			"resolved": "https://registry.npmjs.org/is-bun-module/-/is-bun-module-2.0.0.tgz",
@@ -7721,6 +7775,16 @@
 			"integrity": "sha512-5WUyunoPMsvvEhS8AxHtRzP+oA8UCkJ7YRxatWKjngndhDGLiqEVAQKWjFAiAiuL8zMRGzGSJxFnLetoa43qGQ==",
 			"license": "MIT"
 		},
+		"node_modules/normalize-path": {
+			"version": "3.0.0",
+			"resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-3.0.0.tgz",
+			"integrity": "sha512-6eZs5Ls3WtCisHWp9S2GUy8dqkpGi4BVSz3GaqiE6ezub0512ESztXUwUB6C6IKbQkY2Pnb/mD4WYojCRwcwLA==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=0.10.0"
+			}
+		},
 		"node_modules/object-keys": {
 			"version": "1.1.1",
 			"resolved": "https://registry.npmjs.org/object-keys/-/object-keys-1.1.1.tgz",
@@ -7861,6 +7925,19 @@
 				"url": "https://github.com/sponsors/sindresorhus"
 			}
 		},
+		"node_modules/p-map": {
+			"version": "7.0.4",
+			"resolved": "https://registry.npmjs.org/p-map/-/p-map-7.0.4.tgz",
+			"integrity": "sha512-tkAQEw8ysMzmkhgw8k+1U/iPhWNhykKnSk4Rd5zLoPJCuJaGRPo6YposrZgaxHKzDHdDWWZvE/Sk7hsL2X/CpQ==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=18"
+			},
+			"funding": {
+				"url": "https://github.com/sponsors/sindresorhus"
+			}
+		},
 		"node_modules/parent-module": {
 			"version": "1.0.1",
 			"resolved": "https://registry.npmjs.org/parent-module/-/parent-module-1.0.1.tgz",
@@ -9534,6 +9611,93 @@
 				"uuid": "dist/esm/bin/uuid"
 			}
 		},
+		"node_modules/vite-plugin-static-copy": {
+			"version": "4.1.0",
+			"resolved": "https://registry.npmjs.org/vite-plugin-static-copy/-/vite-plugin-static-copy-4.1.0.tgz",
+			"integrity": "sha512-9XOarNV7LgP0KBB7AApxdgFikLXx3daZdqjC3AevYsL6MrUH62zphonLUs2a6LZc1HN1GY+vQdheZ8VVJb6dQQ==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"chokidar": "^3.6.0",
+				"p-map": "^7.0.4",
+				"picocolors": "^1.1.1",
+				"tinyglobby": "^0.2.15"
+			},
+			"engines": {
+				"node": "^22.0.0 || >=24.0.0"
+			},
+			"funding": {
+				"type": "github",
+				"url": "https://github.com/sponsors/sapphi-red"
+			},
+			"peerDependencies": {
+				"vite": "^6.0.0 || ^7.0.0 || ^8.0.0"
+			}
+		},
+		"node_modules/vite-plugin-static-copy/node_modules/chokidar": {
+			"version": "3.6.0",
+			"resolved": "https://registry.npmjs.org/chokidar/-/chokidar-3.6.0.tgz",
+			"integrity": "sha512-7VT13fmjotKpGipCW9JEQAusEPE+Ei8nl6/g4FBAmIm0GOOLMua9NDDo/DWp0ZAxCr3cPq5ZpBqmPAQgDda2Pw==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"anymatch": "~3.1.2",
+				"braces": "~3.0.2",
+				"glob-parent": "~5.1.2",
+				"is-binary-path": "~2.1.0",
+				"is-glob": "~4.0.1",
+				"normalize-path": "~3.0.0",
+				"readdirp": "~3.6.0"
+			},
+			"engines": {
+				"node": ">= 8.10.0"
+			},
+			"funding": {
+				"url": "https://paulmillr.com/funding/"
+			},
+			"optionalDependencies": {
+				"fsevents": "~2.3.2"
+			}
+		},
+		"node_modules/vite-plugin-static-copy/node_modules/glob-parent": {
+			"version": "5.1.2",
+			"resolved": "https://registry.npmjs.org/glob-parent/-/glob-parent-5.1.2.tgz",
+			"integrity": "sha512-AOIgSQCepiJYwP3ARnGx+5VnTu2HBYdzbGP45eLw1vr3zB3vZLeyed1sC9hnbcOc9/SrMyM5RPQrkGz4aS9Zow==",
+			"dev": true,
+			"license": "ISC",
+			"dependencies": {
+				"is-glob": "^4.0.1"
+			},
+			"engines": {
+				"node": ">= 6"
+			}
+		},
+		"node_modules/vite-plugin-static-copy/node_modules/picomatch": {
+			"version": "2.3.2",
+			"resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.3.2.tgz",
+			"integrity": "sha512-V7+vQEJ06Z+c5tSye8S+nHUfI51xoXIXjHQ99cQtKUkQqqO1kO/KCJUfZXuB47h/YBlDhah2H3hdUGXn8ie0oA==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=8.6"
+			},
+			"funding": {
+				"url": "https://github.com/sponsors/jonschlinkert"
+			}
+		},
+		"node_modules/vite-plugin-static-copy/node_modules/readdirp": {
+			"version": "3.6.0",
+			"resolved": "https://registry.npmjs.org/readdirp/-/readdirp-3.6.0.tgz",
+			"integrity": "sha512-hOS089on8RduqdbhvQ5Z37A0ESjsqz6qnRcffsMU3495FuTdqSm+7bhJ29JvIOsBDEEnan5DPu9t3To9VRlMzA==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"picomatch": "^2.2.1"
+			},
+			"engines": {
+				"node": ">=8.10.0"
+			}
+		},
 		"node_modules/vite/node_modules/fsevents": {
 			"version": "2.3.3",
 			"resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.3.tgz",

frontend/package.json

@@ -68,6 +68,7 @@
 		"typescript-eslint": "^8.47.0",
 		"vite": "^7.3.3",
 		"vite-plugin-devtools-json": "^1.0.0",
+		"vite-plugin-static-copy": "^4.1.0",
 		"vitest": "^4.0.10",
 		"vitest-browser-svelte": "^2.0.1"
 	}

frontend/vite.config.ts

@@ -5,6 +5,7 @@ import tailwindcss from '@tailwindcss/vite';
 import { defineConfig } from 'vitest/config';
 import { playwright } from '@vitest/browser-playwright';
 import { sveltekit } from '@sveltejs/kit/vite';
+import { viteStaticCopy } from 'vite-plugin-static-copy';
 
 export default defineConfig({
 	optimizeDeps: {
@@ -42,6 +43,15 @@ export default defineConfig({
 		tailwindcss(),
 		sveltekit(),
 		devtoolsJson(),
+		// pdf.js 5.x decodes JBIG2 / CCITTFax / JPEG2000 images in WebAssembly.
+		// Serve the wasm from our own origin at /pdfjs-wasm/ (referenced by
+		// getDocument's wasmUrl) — emitted into build/client/ so it survives the
+		// production Docker image, not just `npm run dev`. See issue #708.
+		viteStaticCopy({
+			targets: [
+				{ src: 'node_modules/pdfjs-dist/wasm/*', dest: 'pdfjs-wasm', rename: { stripBase: true } }
+			]
+		}),
 		paraglideVitePlugin({
 			project: './project.inlang',
 			outdir: './src/lib/paraglide'