Implement email-based 2FA authentication for Telegram bot with Oracle integration fixes

This commit adds a complete email authentication flow for the Telegram bot, allowing users to login with email + password instead of web app linking codes. Includes critical bug fixes for Oracle integration.

**New Features:**
- Email-based 2FA authentication with 6-digit codes sent via SMTP
- Backend endpoints: verify-email and login-with-email
- ConversationHandler for email authentication flow in Telegram bot
- Session token verification to prevent user ID spoofing
- Rate limiting (5 attempts per 5 minutes)
- Email code expiry (5 minutes) with automatic cleanup

**Bug Fixes:**
- Fixed Oracle column name: ACTIV → INACTIV (with inverted logic)
- Fixed Oracle password verification: verificautilizator returns checksum, not user_id
- Fixed username case sensitivity: Oracle usernames must be uppercase
- Fixed SMTP connection: use start_tls parameter instead of manual STARTTLS
- Added middleware exclusions for public email auth endpoints

**Backend Changes:**
- Added verify-email endpoint (public) in telegram.py
- Added login-with-email endpoint (public) with rate limiting and session verification
- Updated middleware exclusions in main.py and auth_middleware_wrapper.py
- Added AUTH_SESSION_SECRET configuration for session token signing

**Telegram Bot Changes:**
- New modules: app/auth/email_auth.py, app/bot/email_handlers.py
- New utilities: app/utils/email_service.py (SMTP email sending)
- Updated handlers.py: ignore callbacks handled by ConversationHandler
- Updated menus.py: show Login button for unauthenticated users
- Updated API client: verify_email() and login_with_email() methods
- Database: email_auth_codes table with cleanup task

**Configuration:**
- Added SMTP configuration to telegram-bot .env.example
- Added AUTH_SESSION_SECRET to backend .env.example
- Updated .gitignore: exclude temporary files (*.pid, *.checksum, test scripts)

**Dependencies:**
- Added aiosmtplib for async SMTP email sending

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

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

reports-app/telegram-bot/.env.example

@@ -41,6 +41,32 @@ CLAUDE_API_KEY=
 # Docker: http://roa-backend:8000
 BACKEND_URL=http://roa-backend:8000
 
+# ============================================================================
+# EMAIL AUTHENTICATION (SMTP) CONFIGURATION
+# ============================================================================
+# Required for email-based 2FA authentication flow
+# Users can login with email + password instead of web app linking
+
+# SMTP Server Configuration
+SMTP_HOST=mail.romfast.ro
+SMTP_PORT=587
+SMTP_USER=ups@romfast.ro
+SMTP_PASSWORD=your_smtp_password_here
+SMTP_FROM_EMAIL=ups@romfast.ro
+SMTP_FROM_NAME=ROA2WEB
+SMTP_USE_TLS=true
+
+# Email Sending Settings
+EMAIL_MAX_RETRIES=3
+EMAIL_RETRY_DELAY=2.0
+EMAIL_CODE_EXPIRY_MINUTES=5
+EMAIL_CODE_LENGTH=6
+MAX_EMAIL_ATTEMPTS_PER_HOUR=3
+
+# Session Security (must match backend AUTH_SESSION_SECRET)
+# Generate with: python3 -c "import secrets; print(secrets.token_urlsafe(32))"
+AUTH_SESSION_SECRET=your-secure-random-secret-here-min-32-chars
+
 # ============================================================================
 # DATABASE CONFIGURATION
 # ============================================================================