Use npm ci with fallback to npm install --force

Try npm ci first for faster/reliable installs, fall back to npm install --force if that fails.

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

Dockerfile

@@ -2,7 +2,7 @@ FROM node:20-slim
 
 ENV DEBIAN_FRONTEND=noninteractive
 
-# Build timestamp: 2026-01-12T23:20
+# Build timestamp: 2026-01-12T23:30
 
 RUN apt-get update && apt-get install -y curl git git-lfs && rm -rf /var/lib/apt/lists/*
 
@@ -22,10 +22,10 @@ COPY trigo-web/backend/package-lock.json ./backend/package-lock.json
 RUN npm install -g tsx esbuild
 
 # Install root deps (production only)
-RUN npm install --omit=dev
+RUN npm ci --omit=dev || npm install --omit=dev --force
 
-# Install backend deps
-RUN cd backend && npm install
+# Install backend deps with retry
+RUN cd backend && (npm ci || npm install --force)
 
 # Copy backend source
 COPY trigo-web/backend/src/ ./backend/src/