Fix class name mismatches in hello_world.md and launchpad.md

- hello_world.md: Text referenced Z2UI5_CL_APP_HELLO_WORLD but code defines zcl_app_hello_world, aligned to ZCL_APP_HELLO_WORLD
- launchpad.md: OData URL filter referenced z2ui5_cl_proxy_kpi_hello_world but code defines z2ui5_cl_lp_kpi_hello_world, aligned to match

https://claude.ai/code/session_01AaA4EMw83KMzGP6kaDZPJU

Author: claude

docs/configuration/launchpad.md

@@ -97,5 +97,5 @@ ENDCLASS.
 ```
 (3/3) A generic OData service takes care of everything else (which just returns n dummy entries). Just maintain the KPI at the Launchpad with the following endpoint:
 ```
-.../sap/opu/odata/sap/Z2UI5_PROXY_KPI_SRV/ENTITYCollection/$count?$filter=CLASS eq 'z2ui5_cl_proxy_kpi_hello_world'
+.../sap/opu/odata/sap/Z2UI5_PROXY_KPI_SRV/ENTITYCollection/$count?$filter=CLASS eq 'z2ui5_cl_lp_kpi_hello_world'
 ```

docs/get_started/hello_world.md

@@ -21,7 +21,7 @@ CLASS zcl_app_hello_world IMPLEMENTATION.
   ENDMETHOD.
 ENDCLASS.
 ```
-Head back to the landing page in your browser and enter `Z2UI5_CL_APP_HELLO_WORLD` to launch your app.
+Head back to the landing page in your browser and enter `ZCL_APP_HELLO_WORLD` to launch your app.
 
 ### View Display
 Now let's add a view to display a simple text: