fix: docker packages and IP parsing for 127.0.0.1

.dockerignore

@@ -1 +1,2 @@
 .env
+kittyurl-frontend/node_modules

Dockerfile

@@ -1,11 +1,12 @@
 # Credit: https://www.digitalocean.com/community/tutorials/how-to-build-a-node-js-application-with-docker
+# https://stackoverflow.com/a/56941391
 
 FROM node:24-trixie-slim AS builder
 
 WORKDIR /app
 COPY ./kittyurl-frontend/package*.json ./
 RUN npm ci && npm cache clean --force
-COPY ./kittyurl-frontend/ .
+COPY ./kittyurl-frontend/. ./
 RUN npm run build
 
 FROM node:24-trixie-slim AS production

kittyurl-frontend/src/App.tsx

@@ -11,6 +11,13 @@ export type View = 'home' | 'login' | 'history' | 'jump-game' | 'flappy-game';
 
 const getSubdomain = () => {
     const hostname = window.location.hostname;
+    // Handle localhost and 127.0.0.1 cases.
+    // For more advanced cases (like bare IP hosting)
+    // a regex may be necessary.
+    if (hostname === 'localhost' || hostname === '127.0.0.1') {
+        return null;
+    }
+    
     const parts = hostname.split('.');
     if (parts.length <= 2) return null;
     return parts[0];