chore: add netlify.toml with build config, cache headers, and SPA redirect

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

netlify.toml

@@ -0,0 +1,20 @@
+[build]
+  command = "npm run build"
+  publish = "dist"
+
+[[headers]]
+  for = "/*"
+  [headers.values]
+    X-Frame-Options = "SAMEORIGIN"
+    X-Content-Type-Options = "nosniff"
+    Referrer-Policy = "strict-origin-when-cross-origin"
+
+[[headers]]
+  for = "/assets/*"
+  [headers.values]
+    Cache-Control = "public, max-age=31536000, immutable"
+
+[[redirects]]
+  from = "/*"
+  to = "/index.html"
+  status = 200