Fix LLM validation and dashboard health hot paths

frontend/src/components/llm/ProviderConfig.svelte

@@ -142,10 +142,15 @@
     togglingProviderIds = new Set(togglingProviderIds);
 
     try {
-      await requestApi(`/llm/providers/${provider.id}`, "PUT", {
-        ...provider,
+      const updatePayload = {
+        id: provider.id,
+        name: provider.name,
+        provider_type: provider.provider_type,
+        base_url: provider.base_url,
+        default_model: provider.default_model,
         is_active: provider.is_active,
-      });
+      };
+      await requestApi(`/llm/providers/${provider.id}`, "PUT", updatePayload);
     } catch (err) {
       provider.is_active = previousState;
       providers = [...providers];

frontend/src/components/llm/__tests__/provider_config.integration.test.js

@@ -46,6 +46,15 @@ describe('ProviderConfig edit interaction contract', () => {
     expect(source).toContain('await requestApi(`/llm/providers/${provider.id}`, "DELETE")');
     expect(source).toContain('onclick={() => handleDelete(provider)}');
   });
+
+  it('does not forward masked api_key when toggling provider activation', () => {
+    const source = fs.readFileSync(COMPONENT_PATH, 'utf-8');
+
+    expect(source).toContain('const updatePayload = {');
+    expect(source).toContain('provider_type: provider.provider_type');
+    expect(source).toContain('default_model: provider.default_model');
+    expect(source).not.toContain('await requestApi(`/llm/providers/${provider.id}`, "PUT", {\n        ...provider,');
+  });
 });
 // [/DEF:provider_config_edit_contract_tests:Function]
 // [/DEF:frontend.src.components.llm.__tests__.provider_config_integration:Module]