chore: merge PRs #581, #582 + local improvements for rc16

Merged PRs:
- #582 — model prefix stripping option (closes #568)
- #581 — npm publish workflow fix (refs #579)

Local changes:
- Restored stashed i18n, CLI tools, and maintenance banner updates
- 926 tests passing

scripts/build-next-isolated.mjs

@@ -0,0 +1,84 @@
+#!/usr/bin/env node
+
+import fs from "node:fs/promises";
+import path from "node:path";
+import { spawn } from "node:child_process";
+
+/**
+ * This repository contains a legacy `app/` snapshot (packaging/runtime artifacts)
+ * alongside the active Next.js source in `src/app/`. Next.js route discovery scans
+ * both and fails the build on legacy files. We temporarily move the legacy folder
+ * out of the project root during `next build`, then restore it in all outcomes.
+ */
+
+const projectRoot = process.cwd();
+const legacyAppDir = path.join(projectRoot, "app");
+const backupDir = path.join(projectRoot, `.app-build-backup-${process.pid}-${Date.now()}`);
+
+async function exists(targetPath) {
+  try {
+    await fs.access(targetPath);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+function runNextBuild() {
+  return new Promise((resolve) => {
+    const nextBin = path.join(projectRoot, "node_modules", "next", "dist", "bin", "next");
+    const child = spawn(process.execPath, [nextBin, "build"], {
+      cwd: projectRoot,
+      stdio: "inherit",
+      env: process.env,
+    });
+
+    const forward = (signal) => {
+      if (!child.killed) child.kill(signal);
+    };
+
+    process.on("SIGINT", forward);
+    process.on("SIGTERM", forward);
+
+    child.on("exit", (code, signal) => {
+      process.off("SIGINT", forward);
+      process.off("SIGTERM", forward);
+      if (signal) {
+        resolve({ code: 1, signal });
+        return;
+      }
+      resolve({ code: code ?? 1, signal: null });
+    });
+  });
+}
+
+async function main() {
+  let moved = false;
+
+  try {
+    if (await exists(legacyAppDir)) {
+      await fs.rename(legacyAppDir, backupDir);
+      moved = true;
+    }
+
+    const result = await runNextBuild();
+    process.exitCode = result.code;
+  } catch (error) {
+    console.error("[build-next-isolated] Build failed:", error);
+    process.exitCode = 1;
+  } finally {
+    if (moved) {
+      try {
+        await fs.rename(backupDir, legacyAppDir);
+      } catch (restoreError) {
+        console.error(
+          `[build-next-isolated] Failed to restore legacy app dir from ${backupDir}:`,
+          restoreError
+        );
+        process.exitCode = 1;
+      }
+    }
+  }
+}
+
+await main();