feat: Add A-Z filter for clients/suppliers in Telegram bot

- Add A-Z alphabetical filter keyboard for clients and suppliers lists
  (same pattern as company selection, without emoji)
- Increase clients/suppliers list pagination from 10 to 20 items per page
- Remove emoji from company A-Z filter button for consistency
- Add 6 new callback handlers: clients_alpha_menu, clients_alpha:LETTER,
  clients_alpha_page:PAGE:LETTER, and supplier equivalents
- Dashboard service and models updates
- Telegram bot: email handlers, auth, DB operations, internal API improvements
- Frontend: dashboard cards updates (CashFlow, Clienti, Furnizori, Treasury)
- Frontend: SolduriCompactCard and CollapsibleCard improvements
- DashboardView enhancements
- start.sh and run-with-restart.sh script updates
- IIS web.config and service worker updates

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/modules/telegram/db/database.py

@@ -148,6 +148,14 @@ async def init_database() -> None:
                 ON email_auth_codes(expires_at)
             """)
 
+            # Migration: add server_id column to telegram_auth_codes if missing
+            try:
+                await db.execute("ALTER TABLE telegram_auth_codes ADD COLUMN server_id TEXT")
+                await db.commit()
+                logger.info("Migration: added server_id column to telegram_auth_codes")
+            except Exception:
+                pass  # Column already exists
+
             await db.commit()
             logger.info("Database initialized successfully")