settingsPage Init selfhost (#4734)

# Description of Changes

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Please provide a summary of the changes, including:

- What was changed
- Why the change was made
- Any challenges encountered

Closes #(issue_number)
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---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

---------

Co-authored-by: James Brunton <[email protected]>

frontend/src/core/services/accountService.ts

@@ -0,0 +1,34 @@
+import apiClient from '@app/services/apiClient';
+
+export interface AccountData {
+  username: string;
+  role: string;
+  settings: string; // JSON string of settings
+  changeCredsFlag: boolean;
+  oAuth2Login: boolean;
+  saml2Login: boolean;
+}
+
+/**
+ * Account Service
+ * Provides functions to interact with account-related backend APIs
+ */
+export const accountService = {
+  /**
+   * Get current user account data
+   */
+  async getAccountData(): Promise<AccountData> {
+    const response = await apiClient.get<AccountData>('/api/v1/proprietary/ui-data/account');
+    return response.data;
+  },
+
+  /**
+   * Change user password
+   */
+  async changePassword(currentPassword: string, newPassword: string): Promise<void> {
+    const formData = new FormData();
+    formData.append('currentPassword', currentPassword);
+    formData.append('newPassword', newPassword);
+    await apiClient.post('/api/v1/user/change-password', formData);
+  },
+};