Initial Renamr scaffold: Tauri (Rust core + React/TS UI), naming-expression engine ported+tested

src/App.tsx

@@ -0,0 +1,65 @@
+import { useEffect, useState } from "react";
+import { invoke } from "@tauri-apps/api/core";
+
+const APP_NAME = "Renamr";
+const APP_VERSION = "0.1.0";
+
+const DEFAULT_EXPRESSION = "{n} - {s00e00} - {t}";
+const DEFAULT_BINDINGS: Record<string, string> = {
+  n: "Example Show",
+  s00e00: "S01E01",
+  t: "Pilot",
+};
+
+export default function App() {
+  const [expression, setExpression] = useState(DEFAULT_EXPRESSION);
+  const [preview, setPreview] = useState<string>("");
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    let cancelled = false;
+
+    invoke<string>("render_expression", { expression, bindings: DEFAULT_BINDINGS })
+      .then((result) => {
+        if (!cancelled) {
+          setPreview(result);
+          setError(null);
+        }
+      })
+      .catch((err) => {
+        if (!cancelled) {
+          setPreview("");
+          setError(String(err));
+        }
+      });
+
+    return () => {
+      cancelled = true;
+    };
+  }, [expression]);
+
+  return (
+    <main className="shell">
+      <header>
+        <h1>{APP_NAME}</h1>
+        <p className="tagline">A fast, cross-platform media renamer.</p>
+        <p className="version">v{APP_VERSION}</p>
+      </header>
+
+      <section className="panel">
+        <label htmlFor="expression">Naming scheme</label>
+        <input
+          id="expression"
+          value={expression}
+          onChange={(e) => setExpression(e.target.value)}
+          spellCheck={false}
+        />
+
+        <div className="preview">
+          <span className="preview-label">Preview</span>
+          {error ? <span className="preview-error">{error}</span> : <span className="preview-value">{preview}</span>}
+        </div>
+      </section>
+    </main>
+  );
+}