feat(auth): add auto-generation of oauth credentials

Implement functionality to create the oauth_creds.json file from
environment variables (ACCESS_TOKEN, REFRESH_TOKEN, EXPIRY_DATE)
if the file is missing. Also update documentation, docker-compose,
and build scripts to support this new feature.

Dockerfile

@@ -0,0 +1,26 @@
+# Use an official Node.js runtime as a parent image
+FROM node:22.15-slim
+
+# Set the working directory in the container
+WORKDIR /usr/src/app
+
+# Create directory for oauth credentials
+RUN mkdir -p /root/.gemini
+
+# Copy package.json and package-lock.json to the working directory
+COPY package*.json ./
+
+# Install any needed packages specified in package.json
+RUN npm install
+
+# Bundle app source
+COPY . .
+
+# Build the typescript code
+RUN npm run build
+
+# Make port 4343 available to the world outside this container
+EXPOSE 4343
+
+# Define the command to run the app
+CMD [ "npm", "start" ]