fix: Fix policy creation API field mapping to match backend expectations

- Update createPolicy to send 'policyName' and 'policyDocument' fields
- Update attachPolicy to use correct endpoint format /policies/{name}/attach
- Send 'username' field in attachPolicy request body

This fixes the 'Validation Error' when creating policies in QuickStartWizard
and ensures policies are created and attached correctly to users.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/src/services/policyService.ts

@@ -111,7 +111,10 @@ class PolicyService {
 
   async createPolicy(policyData: CreatePolicyRequest): Promise<void> {
     try {
-      await axios.post(`${this.baseURL}/policies`, policyData, {
+      await axios.post(`${this.baseURL}/policies`, {
+        policyName: policyData.name,
+        policyDocument: policyData.policy,
+      }, {
         headers: getAuthHeaders(),
       });
     } catch (error) {
@@ -151,7 +154,9 @@ class PolicyService {
 
   async attachPolicy(data: AttachPolicyRequest): Promise<void> {
     try {
-      await axios.post(`${this.baseURL}/policies/attach`, data, {
+      await axios.post(`${this.baseURL}/policies/${data.policyName}/attach`, {
+        username: data.userName,
+      }, {
         headers: getAuthHeaders(),
       });
     } catch (error) {