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/app/main.py

@@ -30,7 +30,12 @@ from telegram.ext import (
 )
 
 # Import database initialization
-from app.db import init_database, cleanup_expired_codes, cleanup_expired_sessions
+from app.db import (
+    init_database,
+    cleanup_expired_codes,
+    cleanup_expired_sessions,
+    cleanup_expired_email_codes
+)
 
 # Import bot handlers
 from app.bot.handlers import (
@@ -61,6 +66,9 @@ from app.bot.handlers import (
     error_handler
 )
 
+# Import email authentication handler
+from app.bot.email_handlers import email_login_handler
+
 # Import internal API
 from app.internal_api import internal_api
 
@@ -93,6 +101,9 @@ def create_telegram_application() -> Application:
     # Create application
     application = Application.builder().token(TELEGRAM_BOT_TOKEN).build()
 
+    # Register email authentication conversation handler (must be before other handlers)
+    application.add_handler(email_login_handler)
+
     # Register essential command handlers
     application.add_handler(CommandHandler("start", start_command))
     application.add_handler(CommandHandler("menu", menu_command))
@@ -186,7 +197,8 @@ async def startup():
         logger.info("Cleaning up expired data...")
         expired_codes = await cleanup_expired_codes()
         expired_sessions = await cleanup_expired_sessions()
-        logger.info(f"✅ Cleanup complete: {expired_codes} codes, {expired_sessions} sessions removed")
+        expired_email_codes = await cleanup_expired_email_codes()
+        logger.info(f"✅ Cleanup complete: {expired_codes} codes, {expired_sessions} sessions, {expired_email_codes} email codes removed")
     except Exception as e:
         logger.warning(f"⚠️ Cleanup failed (non-critical): {e}")
 
@@ -204,7 +216,7 @@ async def shutdown():
 async def scheduled_cleanup():
     """
     Background task to periodically clean up expired data.
-    Runs every hour to remove expired auth codes and sessions.
+    Runs every hour to remove expired auth codes, sessions, and email codes.
     """
     while True:
         try:
@@ -212,7 +224,8 @@ async def scheduled_cleanup():
             logger.info("🧹 Running scheduled cleanup...")
             expired_codes = await cleanup_expired_codes()
             expired_sessions = await cleanup_expired_sessions()
-            logger.info(f"✅ Scheduled cleanup: {expired_codes} codes, {expired_sessions} sessions removed")
+            expired_email_codes = await cleanup_expired_email_codes()
+            logger.info(f"✅ Scheduled cleanup: {expired_codes} codes, {expired_sessions} sessions, {expired_email_codes} email codes removed")
         except Exception as e:
             logger.error(f"❌ Error in scheduled cleanup: {e}")