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/routers/internal_api.py

@@ -56,6 +56,10 @@ class SaveAuthCodeRequest(BaseModel):
         ge=1,
         le=60
     )
+    server_id: Optional[str] = Field(
+        default=None,
+        description="Oracle server ID (for multi-server mode)"
+    )
 
 
 class SaveAuthCodeResponse(BaseModel):
@@ -151,7 +155,8 @@ async def save_auth_code(request: SaveAuthCodeRequest):
             code=request.code,
             telegram_user_id=request.telegram_user_id,
             oracle_username=request.oracle_username,
-            expires_in_minutes=request.expires_in_minutes
+            expires_in_minutes=request.expires_in_minutes,
+            server_id=request.server_id
         )
 
         if not success: