Simplify dev scripts (#294)

* Update scripts

* Update FE build

scripts/cargo.js

@@ -1,31 +0,0 @@
-#!/usr/bin/env node
-/**
- * Drop-in replacement for the `cargo` binary.
- * If CARGO_TARGET_DIR is already set we leave it alone.
- * Otherwise we compute a path that is the same for every git-worktree:
- *   <main-clone-root>/target
- *
- * Usage   :  node scripts/cargo.js <cargo-subcommand> […]
- * NPM     :  "backend:build": "node scripts/cargo.js build --release …"
- */
-const { spawnSync, execSync } = require('node:child_process');
-const path = require('node:path');
-
-function sharedTarget() {
-  try {
-    // Works in any work-tree folder
-    const common = execSync('git rev-parse --git-common-dir', { encoding: 'utf8' }).trim();
-    return path.resolve(common, '..', 'target');
-  } catch {
-    return undefined;                 // not a git repo? -> let Cargo use ./target
-  }
-}
-
-const env = { ...process.env };
-if (!env.CARGO_TARGET_DIR) {
-  const dir = sharedTarget();
-  if (dir) env.CARGO_TARGET_DIR = dir;
-}
-
-const result = spawnSync('cargo', process.argv.slice(2), { stdio: 'inherit', env });
-process.exitCode = result.status;