Fix numeroContrato: use EMPRESA.CODCONTRATO from Firebird, sucursal default 00

- Join EMPRESA table in all RDA queries to get CODCONTRATO (TNS contract code)
- Use EMPRESA.CODCONTRATO as numeroContrato instead of raw NIT_EMPRESA
- Especialidad always uses default_especialidad (ignore Firebird COD_ESPECIALIDAD)
- sucursal defaults to '00' (not empty) in config and endpoints
- Fix config template label: especialidad default is TNS code not Firebird code

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

app/routes/transaccion.py

@@ -147,10 +147,8 @@ async def send_transaccion(
         return JSONResponse({"success": False, "message": f"Error login TNS: {token_err}"})
 
     headers = {"Content-Type": "application/json", "Authorization": f"Bearer {token}"}
-    api_sucursal = configs.get("api_sucursal", "")
-    endpoint = f"{TNS_BASE}/v2/rda/RdaPaciente/Insertar"
-    if api_sucursal:
-        endpoint += f"?codigosucursal={api_sucursal}"
+    api_sucursal = configs.get("api_sucursal", "") or "00"
+    endpoint = f"{TNS_BASE}/v2/rda/RdaPaciente/Insertar?codigosucursal={api_sucursal}"
 
     total_enviados = 0
     total_errores = 0