fix: patch scaffold URL parser to support self-hosted Gitea (.eu TLD)

zotero-plugin-scaffold hardcodes a .com-only regex in parseRepoUrl,
causing build failures with non-.com repository URLs. Add:
- scripts/patch-scaffold.mjs: postinstall script that fixes the regex
- zotero-plugin.config.ts: explicit xpiDownloadLink and updateURL
  so scaffold generates correct update.json without relying on the parser

zotero-plugin.config.ts

@@ -1,12 +1,18 @@
 import { defineConfig } from "zotero-plugin-scaffold";
 import pkg from "./package.json";
 
+const GITEA_BASE = "https://gitea.bueso.eu/ignacio.ballesteros/zotero-notes-export-org";
+
 export default defineConfig({
   source: ["src", "addon"],
   dist: ".scaffold/build",
   name: pkg.config.addonName,
   id: pkg.config.addonID,
   namespace: pkg.config.addonRef,
+  // Explicit URLs are required because zotero-plugin-scaffold's URL parser
+  // only handles .com domains and cannot parse our self-hosted Gitea instance.
+  xpiDownloadLink: `${GITEA_BASE}/releases/download/v{{version}}/{{xpiName}}.xpi`,
+  updateURL: `${GITEA_BASE}/releases/download/release/{{updateJson}}`,
   build: {
     esbuildOptions: [
       {