feat(devcontainer): pre-cache npm and maven dependencies in image

- npm dependencies (root + frontend) now cached in docker image
- maven dependencies downloaded during image build
- post-create.sh restores from cache for faster startup
- reduces new developer setup time significantly

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: MohsinHashmi-DataInn

.devcontainer/Dockerfile

@@ -40,10 +40,47 @@ ENV PLAYWRIGHT_CHROMIUM_EXECUTABLE_PATH=/usr/bin/chromium
 # Install global npm packages
 RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && npm install -g npm@latest" 2>&1
 
-# Pre-cache Maven dependencies (optional - speeds up first build)
-# Uncomment if you want to pre-download Maven dependencies
-# COPY apps/backend/pom.xml /tmp/pom.xml
-# RUN cd /tmp && mvn dependency:go-offline -B
+# ============================================
+# PRE-CACHE DEPENDENCIES FOR FASTER STARTUP
+# ============================================
+
+# Create cache directories
+RUN mkdir -p /home/vscode/.npm-cache /home/vscode/.m2-cache \
+    && chown -R vscode:vscode /home/vscode/.npm-cache /home/vscode/.m2-cache
+
+# --- NPM Dependencies ---
+# Copy package files for dependency caching
+COPY --chown=vscode:vscode package*.json /tmp/deps/
+COPY --chown=vscode:vscode apps/frontend/package*.json /tmp/deps/apps/frontend/
+
+# Install root npm dependencies
+RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && cd /tmp/deps && npm install" 2>&1
+
+# Install frontend npm dependencies
+RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && cd /tmp/deps/apps/frontend && npm install --legacy-peer-deps" 2>&1
+
+# --- Maven Dependencies ---
+# Copy pom.xml for Maven dependency caching
+COPY --chown=vscode:vscode apps/backend/pom.xml /tmp/deps/apps/backend/
+COPY --chown=vscode:vscode apps/backend/.mvn /tmp/deps/apps/backend/.mvn/
+COPY --chown=vscode:vscode apps/backend/mvnw /tmp/deps/apps/backend/
+
+# Download Maven dependencies
+RUN cd /tmp/deps/apps/backend \
+    && chmod +x mvnw \
+    && ./mvnw dependency:go-offline -B -q || true
+
+# Move cached dependencies to persistent locations
+RUN cp -r /tmp/deps/node_modules /home/vscode/.npm-cache/root-node_modules 2>/dev/null || true \
+    && cp -r /tmp/deps/apps/frontend/node_modules /home/vscode/.npm-cache/frontend-node_modules 2>/dev/null || true \
+    && chown -R vscode:vscode /home/vscode/.npm-cache /home/vscode/.m2
+
+# Cleanup temp files
+RUN rm -rf /tmp/deps
+
+# ============================================
+# END DEPENDENCY CACHING
+# ============================================
 
 # Set working directory
 WORKDIR /workspaces/SimpleAccounts-UAE

.devcontainer/post-create.sh

@@ -5,24 +5,40 @@ set -e
 
 echo "🚀 Setting up SimpleAccounts-UAE development environment..."
 
-# Install root dependencies
-echo "📦 Installing root npm dependencies..."
-npm install
+# --- Use cached npm dependencies if available ---
+if [ -d "/home/vscode/.npm-cache/root-node_modules" ]; then
+    echo "📦 Restoring cached root npm dependencies..."
+    cp -r /home/vscode/.npm-cache/root-node_modules ./node_modules
+    # Quick install to sync any new packages
+    npm install --prefer-offline 2>/dev/null || npm install
+else
+    echo "📦 Installing root npm dependencies..."
+    npm install
+fi
 
-# Install frontend dependencies
-echo "📦 Installing frontend dependencies..."
-cd apps/frontend
-npm install --legacy-peer-deps
-cd ../..
+if [ -d "/home/vscode/.npm-cache/frontend-node_modules" ]; then
+    echo "📦 Restoring cached frontend npm dependencies..."
+    cp -r /home/vscode/.npm-cache/frontend-node_modules ./apps/frontend/node_modules
+    # Quick install to sync any new packages
+    cd apps/frontend
+    npm install --legacy-peer-deps --prefer-offline 2>/dev/null || npm install --legacy-peer-deps
+    cd ../..
+else
+    echo "📦 Installing frontend dependencies..."
+    cd apps/frontend
+    npm install --legacy-peer-deps
+    cd ../..
+fi
 
 # Install Playwright browsers (using system Chromium)
 echo "🎭 Setting up Playwright..."
 cd apps/frontend
 npx playwright install-deps 2>/dev/null || true
 cd ../..
 
-# Download Maven dependencies (this can take a while on first run)
-echo "☕ Downloading Maven dependencies..."
+# Maven dependencies are cached in ~/.m2 which is a named volume
+# Just ensure any new dependencies are downloaded
+echo "☕ Syncing Maven dependencies..."
 cd apps/backend
 if [ -f "./mvnw" ]; then
     chmod +x ./mvnw