chore: lock the plugin boundary and remove 2.9.0 leftovers

vitest.config.ts

@@ -1,36 +1,7 @@
-import fs from "fs";
 import path from "path";
-import { defineConfig, type Plugin } from "vitest/config";
-
-/**
- * The built plugin bundles the boot tests load (dist/plugins) still reach
- * compiled core by relative path for a few plugins. Point those imports at
- * core's source, so the bundle shares the one database and the singletons the
- * test booted instead of loading a second, uninitialized copy of core.
- */
-function builtPluginCoreImports(): Plugin {
-  return {
-    name: "built-plugin-core-imports",
-    enforce: "pre",
-    resolveId(source, importer) {
-      if (!importer || !source.startsWith(".")) return null;
-      if (!importer.replace(/\\/g, "/").includes("/dist/plugins/")) return null;
-      const target = path
-        .resolve(path.dirname(importer), source)
-        .replace(/\\/g, "/");
-      const match = /\/dist\/backend\/(backend|types)\/(.*)\.js$/.exec(target);
-      if (!match) return null;
-      const base = path.resolve(__dirname, "src", match[1], match[2]);
-      for (const candidate of [`${base}.ts`, `${base}.tsx`]) {
-        if (fs.existsSync(candidate)) return candidate;
-      }
-      return null;
-    },
-  };
-}
+import { defineConfig } from "vitest/config";
 
 export default defineConfig({
-  plugins: [builtPluginCoreImports()],
   resolve: {
     alias: [
       {
@@ -51,15 +22,6 @@ export default defineConfig({
           "./src/ui/plugin-host/testing-host.tsx",
         ),
       },
-      // What built plugin frontends import instead of "@/...". D1 removes it.
-      {
-        find: /^@termix\/legacy-core\/ui\/(.*)$/,
-        replacement: path.resolve(__dirname, "./src/ui") + "/$1",
-      },
-      {
-        find: /^@termix\/legacy-core\/types(.*)$/,
-        replacement: path.resolve(__dirname, "./src/types") + "$1",
-      },
       { find: "@/types", replacement: path.resolve(__dirname, "./src/types") },
       { find: "@", replacement: path.resolve(__dirname, "./src/ui") },
     ],