refactor (okay, i know that this cannot be merged ; too large diff. I will pick some cheery).

apply-package.mjs

@@ -0,0 +1,42 @@
+// Copy package.json dependencies and devDependencies from the repo root to the target sub-apps package.json, and set their versions to match the repo root version with a suffix.
+import fs from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+const repoRoot = __dirname;
+const repoPackageJsonPath = path.join(repoRoot, "package.json");
+const repoPackageJson = JSON.parse(fs.readFileSync(repoPackageJsonPath, "utf-8"));
+const devDependenciesToCopy = repoPackageJson.devDependencies || {};
+const dependenciesToCopy = repoPackageJson.dependencies || {};
+
+const TARGET_APPS = ["cli", "webapp", "webpeer"];
+
+for (const app of TARGET_APPS) {
+    const appDir = path.join(repoRoot, "src", "apps", app);
+    const packageJsonPath = path.join(appDir, "package.json");
+    if (!fs.existsSync(packageJsonPath)) {
+        continue;
+    }
+    const packageJson = JSON.parse(fs.readFileSync(packageJsonPath, "utf-8"));
+
+    packageJson.dependencies = {
+        ...packageJson.dependencies,
+        ...dependenciesToCopy,
+    };
+    packageJson.devDependencies = {
+        ...packageJson.devDependencies,
+        ...devDependenciesToCopy,
+    };
+    packageJson.version = `${repoPackageJson.version}-${app}`;
+
+    fs.writeFileSync(packageJsonPath, JSON.stringify(packageJson, null, 4), "utf-8");
+    console.log(`Applied package.json dependencies and version from repo root to ${app} package.json`);
+}
+
+console.log("\nApplied dependencies and version to all target applications.");
+console.log(
+    "Please do not forget to pick dependencies that are actually needed in the target package.json, and remove the ones that are not needed."
+);