ci: add CI image builder workflow and Dockerfile

Dockerfile.ci

@@ -0,0 +1,46 @@
+# CI Runner Image for EuchreCamp
+# Pre-installed with all dependencies to speed up CI runs
+# This image is rebuilt automatically when package.json changes
+
+FROM node:20-alpine
+
+# Install system dependencies needed for various tasks
+RUN apk add --no-cache \
+    bash \
+    git \
+    curl \
+    python3 \
+    make \
+    g++ \
+    && rm -rf /var/cache/apk/*
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files first (for better caching)
+COPY package*.json ./
+
+# Install ALL dependencies including dev dependencies
+# This is done at image build time, not at CI runtime
+RUN npm ci
+
+# Copy Prisma schema (needed for Prisma client generation)
+COPY prisma/schema.prisma ./prisma/
+
+# Generate Prisma client
+RUN npx prisma generate
+
+# Copy the rest of the application
+COPY . .
+
+# Set environment variables for CI environment
+ENV NODE_ENV=production
+ENV DATABASE_PROVIDER=sqlite
+ENV DATABASE_URL=file:./prisma/ci.db
+ENV BETTER_AUTH_SECRET=test-secret-key-for-ci-only
+
+# Verify installations
+RUN node --version && npm --version && git --version && npx prisma --version
+
+# Default command
+CMD ["/bin/sh"]