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>

.dockerignore

@@ -0,0 +1,75 @@
+# ============================================
+# Docker Build Context Ignore
+# ============================================
+
+# Version control
+.git
+.gitignore
+
+# IDE
+.vscode
+.idea
+.claude
+.cursor
+.augment
+.clinerules
+.gemini
+.opencode
+.agents
+.agent
+
+# Python
+.venv
+__pycache__
+*.pyc
+*.pyo
+*.egg-info
+dist/
+build/
+
+# Node
+frontend/node_modules
+frontend/.next
+
+# Environment files
+.env
+.env.*
+!.env.example
+
+# Docker (avoid recursive) — keep backend entrypoint and frontend server.js
+docker/nginx/
+docker/prometheus/
+
+# Kubernetes
+k8s/
+
+# Runtime data
+uploads/
+outputs/
+temp/
+logs/
+data/*.db
+data/*.sqlite
+
+# Test
+tests/
+frontend/src/test/
+
+# Documentation
+docs/
+*.md
+!README.md
+
+# Landing page (separate project)
+office-translator-landing-page/
+
+# macOS
+.DS_Store
+
+# Backups
+backups/
+
+# Build artifacts
+*.log
+*.png
+*.jpg