build: streamline Docker setup and environment config

- Simplify Dockerfile to use official Bun image as base
- Add admin bootstrap environment variables to .env.example
- Include VITE_ADMIN_EMAIL and VITE_ADMIN_PASSWORD build args
- Fix newline at end of .env.example file
- Remove redundant system dependency installations

Dockerfile

@@ -1,34 +1,17 @@
 # Multi-stage Dockerfile for Medication Reminder App
-FROM node:20-slim AS base
-
-# Install system dependencies
-RUN apt-get update && apt-get install -y \
-  curl \
-  unzip \
-  && rm -rf /var/lib/apt/lists/*
-
-# Install Bun
-RUN curl -fsSL https://bun.sh/install | bash
-ENV PATH="/root/.bun/bin:$PATH"
+FROM oven/bun:1 AS builder
 
 # Set working directory
 WORKDIR /app
 
-# Create non-root user
-RUN groupadd --gid 1001 nodeuser && \
-  useradd --uid 1001 --gid nodeuser --shell /bin/bash --create-home nodeuser
-
-# Builder stage
-FROM base AS builder
-
 # Copy package files
-COPY --chown=nodeuser:nodeuser package.json bun.lock* ./
+COPY package.json bun.lock* ./
 
 # Install dependencies
 RUN bun install --frozen-lockfile
 
 # Copy source code
-COPY --chown=nodeuser:nodeuser . ./
+COPY . ./
 
 # Build arguments for environment configuration
 # Build Environment - unified config will handle the rest
@@ -40,6 +23,8 @@ ARG NODE_ENV=production
 ARG VITE_COUCHDB_URL
 ARG VITE_COUCHDB_USER
 ARG VITE_COUCHDB_PASSWORD
+ARG VITE_ADMIN_EMAIL
+ARG VITE_ADMIN_PASSWORD
 
 # Set environment variables for build process
 # Unified config handles defaults, only set essential runtime overrides
@@ -47,7 +32,8 @@ ENV NODE_ENV=$NODE_ENV
 ENV VITE_COUCHDB_URL=$VITE_COUCHDB_URL
 ENV VITE_COUCHDB_USER=$VITE_COUCHDB_USER
 ENV VITE_COUCHDB_PASSWORD=$VITE_COUCHDB_PASSWORD
-ENV NODE_ENV=$NODE_ENV
+ENV VITE_ADMIN_EMAIL=$VITE_ADMIN_EMAIL
+ENV VITE_ADMIN_PASSWORD=$VITE_ADMIN_PASSWORD
 
 # Build the application
 RUN bun run build