fix: enforce OMO ↔ OMO Slim cross-category mutual exclusion

When activating an OMO provider, deactivate all OMO Slim providers
in the same transaction and delete the Slim config file, and vice
versa. This prevents both plugin variants from being active
simultaneously.

src-tauri/src/services/provider/mod.rs

@@ -513,6 +513,8 @@ impl ProviderService {
                 state,
                 &crate::services::omo::STANDARD,
             )?;
+            // OMO ↔ OMO Slim mutually exclusive: remove Slim config
+            let _ = crate::services::OmoService::delete_config_file(&crate::services::omo::SLIM);
             return Ok(SwitchResult::default());
         }
 
@@ -522,6 +524,10 @@ impl ProviderService {
                 .db
                 .set_omo_provider_current(app_type.as_str(), id, "omo-slim")?;
             crate::services::OmoService::write_config_to_file(state, &crate::services::omo::SLIM)?;
+            // OMO ↔ OMO Slim mutually exclusive: remove Standard config
+            let _ = crate::services::OmoService::delete_config_file(
+                &crate::services::omo::STANDARD,
+            );
             return Ok(SwitchResult::default());
         }