feat: fix registration 500, add forgot-password flow, frontend validation

- Fix MissingGreenlet: sync_engine now uses psycopg2 instead of asyncpg
- Fix bcrypt/passlib compat: pin bcrypt<4.1 in requirements
- Fix legacy password_hash NOT NULL: alter column to nullable in migration
- Add frontend password validation (uppercase + lowercase + digit)
- Add forgot-password and reset-password backend endpoints
- Add forgot-password and reset-password frontend pages
- Add email_service.py (SMTP via admin settings)
- Add reset_token/reset_token_expires columns to User model
- Migrate legacy JSON-only users to DB on password reset request
- Mount data/ volume in docker-compose.local.yml for persistence
- Add production deployment config (Dockerfile, nginx, deploy.sh)

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

docker/frontend/Dockerfile

@@ -1,49 +1,55 @@
-# Document Translation Frontend - Dockerfile
+# Office Translator - Frontend Dockerfile
 # Multi-stage build for optimized production
 
-# Build stage
+# ---- Build stage ----
 FROM node:20-alpine AS builder
 
 WORKDIR /app
 
-# Copy package files
+# Copy package files first (better layer caching)
 COPY frontend/package*.json ./
 
-# Install dependencies
-RUN npm ci --only=production=false
+# Install ALL dependencies (dev needed for build)
+RUN npm install
 
 # Copy source code
 COPY frontend/ .
 
-# Build arguments for environment
-ARG NEXT_PUBLIC_API_URL=http://localhost:8000
+# Build arguments
+# NEXT_PUBLIC_API_URL: client-side API base (empty = relative URLs via proxy)
+# BACKEND_URL: server-side proxy target (must be resolvable from container)
+ARG NEXT_PUBLIC_API_URL=
+ARG BACKEND_URL=http://backend:8000
 ENV NEXT_PUBLIC_API_URL=${NEXT_PUBLIC_API_URL}
+ENV BACKEND_URL=${BACKEND_URL}
 
-# Build the application
+# Build the application (with standalone output)
 RUN npm run build
 
-# Production stage
+# ---- Production stage ----
 FROM node:20-alpine AS production
 
 WORKDIR /app
 
+# Set NODE_ENV before copying
+ENV NODE_ENV=production
+
 # Create non-root user
 RUN addgroup -g 1001 -S nodejs && \
     adduser -S nextjs -u 1001
 
-# Copy built assets from builder
+# Copy standalone output from builder
 COPY --from=builder /app/public ./public
 COPY --from=builder /app/.next/standalone ./
 COPY --from=builder /app/.next/static ./.next/static
 
-# Set correct permissions
+# Set correct ownership
 RUN chown -R nextjs:nodejs /app
 
 USER nextjs
 
-# Environment
-ENV NODE_ENV=production \
-    PORT=3000 \
+# Runtime environment
+ENV PORT=3000 \
     HOSTNAME="0.0.0.0"
 
 EXPOSE 3000