fix: Simplify Docker build to ensure lib directory is preserved

Remove existing lib directory before copying built files from builder stage
and add Node.js require path testing to debug the module resolution.

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

Co-Authored-By: Claude <[email protected]>

Author: marshallswain

Dockerfile.node12

@@ -40,19 +40,17 @@ COPY package*.json ./
 # Install dependencies
 RUN npm install --no-optional
 
-# Copy package files and source files (but not lib directory)
-COPY --chown=node:node package*.json ./
-COPY --chown=node:node src ./src
-COPY --chown=node:node test ./test
-COPY --chown=node:node types ./types
-COPY --chown=node:node tsconfig.json ./
-COPY --chown=node:node .eslintrc.js ./
+# Copy all files except lib directory first
+COPY --chown=node:node . .
+
+# Remove any existing lib directory to ensure clean copy
+RUN rm -rf lib
 
 # Copy built files from builder stage
 COPY --from=builder /app/lib ./lib
 
 # Debug: Check current working directory and paths
-RUN pwd && ls -la && echo "Contents of lib:" && ls -la lib/
+RUN pwd && ls -la && echo "Contents of lib:" && ls -la lib/ && echo "Testing require path:" && node -e "console.log(require.resolve('./lib/error-handler'))"
 
 # Fix mocha permissions
 RUN chmod +x node_modules/.bin/mocha