fix(pdf-compress): stream large uploads via busboy instead of arrayBuffer

req.arrayBuffer() fails with 502 on files >100MB because it tries to
buffer the entire body in memory before the route handler runs.

New approach: busboy streams the multipart body directly to a temp file
on disk — never buffers the whole request in memory. Works for any size.

Shared helper: parse-upload.ts (busboy streaming, 500MB limit, fields).
Both local (qpdf) and cloud (iLovePDF) routes refactored to use it.

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

package-lock.json

@@ -11,6 +11,7 @@
         "@prisma/client": "^6.19.2",
         "axios": "^1.13.6",
         "axios-cookiejar-support": "^6.0.5",
+        "busboy": "^1.6.0",
         "class-variance-authority": "^0.7.1",
         "clsx": "^2.1.1",
         "docx": "^9.6.0",
@@ -35,6 +36,7 @@
       },
       "devDependencies": {
         "@tailwindcss/postcss": "^4",
+        "@types/busboy": "^1.5.4",
         "@types/jszip": "^3.4.0",
         "@types/node": "^20",
         "@types/nodemailer": "^7.0.11",
@@ -3995,6 +3997,16 @@
         "tslib": "^2.4.0"
       }
     },
+    "node_modules/@types/busboy": {
+      "version": "1.5.4",
+      "resolved": "https://registry.npmjs.org/@types/busboy/-/busboy-1.5.4.tgz",
+      "integrity": "sha512-kG7WrUuAKK0NoyxfQHsVE6j1m01s6kMma64E+OZenQABMQyTJop1DumUWcLwAQ2JzpefU7PDYoRDKl8uZosFjw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/estree": {
       "version": "1.0.8",
       "resolved": "https://registry.npmjs.org/@types/estree/-/estree-1.0.8.tgz",
@@ -5303,6 +5315,17 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/busboy": {
+      "version": "1.6.0",
+      "resolved": "https://registry.npmjs.org/busboy/-/busboy-1.6.0.tgz",
+      "integrity": "sha512-8SFQbg/0hQ9xy3UNTB0YEnsNBbWfhf7RtnzpL7TkBiTBRfrQ9Fxcnz7VJsleJpyp6rVLvXiuORqjlHi5q+PYuA==",
+      "dependencies": {
+        "streamsearch": "^1.1.0"
+      },
+      "engines": {
+        "node": ">=10.16.0"
+      }
+    },
     "node_modules/bytes": {
       "version": "3.1.2",
       "resolved": "https://registry.npmjs.org/bytes/-/bytes-3.1.2.tgz",
@@ -12144,6 +12167,14 @@
         "stream-chain": "^2.2.5"
       }
     },
+    "node_modules/streamsearch": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/streamsearch/-/streamsearch-1.1.0.tgz",
+      "integrity": "sha512-Mcc5wHehp9aXz1ax6bZUyY5afg9u2rv5cqQI3mRrYkGC8rW2hM02jWuwjtL++LS5qinSyhj2QfLyNsuc+VsExg==",
+      "engines": {
+        "node": ">=10.0.0"
+      }
+    },
     "node_modules/strict-event-emitter": {
       "version": "0.5.1",
       "resolved": "https://registry.npmjs.org/strict-event-emitter/-/strict-event-emitter-0.5.1.tgz",