docs(mobile-client): add account management documentation

- Create new documentation page for account management features
- Describe core components: AccountBloc, AccountPage, and SavedHeadlinesPage
- Highlight key functionalities:
  - Centralized user preferences management
  - Saved articles feature
  - Followed content management
  - Anonymous to authenticated user flow
- Use CardGrid component to showcase features visually

Author: fulleni

src/content/docs/mobile-client/features/account.mdx

@@ -0,0 +1,32 @@
+---
+title: Account Management
+description: Learn how users can manage their preferences, saved articles, and followed content.
+---
+import { Card, CardGrid } from '@astrojs/starlight/components';
+
+The Account section serves as the user's personal hub within the application. From here, they can view their profile, manage their content preferences, access saved articles, and control their sign-in status.
+
+## Core Components
+
+-   **`AccountBloc`**: This is the primary BLoC for managing a user's content preferences (`UserContentPreferences`). It listens for changes in the user's authentication state from the `AppBloc`. When a user signs in, it loads their preferences. It also handles all actions related to modifying these preferences, such as saving an article or following a topic.
+
+-   **`AccountPage`**: The main UI for this feature. It displays the user's email or an "Anonymous" status, provides a sign-out or link-account button, and offers navigation to sub-pages for managing saved and followed content.
+
+-   **`SavedHeadlinesPage`**: A dedicated page that displays a list of all the headlines the user has saved. Users can view or remove articles from this list.
+
+## Key Functionalities
+
+<CardGrid>
+	<Card title="Centralized User Preferences" icon="user-cog">
+		The `AccountBloc` is responsible for fetching, creating, and updating a user's `UserContentPreferences` object. This single object holds all of the user's content-related settings, including lists of followed topics, followed sources, and saved headlines.
+	</Card>
+	<Card title="Saved Articles" icon="bookmark">
+		Users can save any headline for later reading. This action dispatches an `AccountSaveHeadlineToggled` event to the `AccountBloc`. The `SavedHeadlinesPage` then displays a clean, scrollable list of these saved articles.
+	</Card>
+	<Card title="Followed Content Management" icon="list-check">
+		The "Content Preferences" section allows users to manage the topics and sources they follow. This is where the `AvailableTopicsBloc` and `AvailableSourcesBloc` are used to fetch lists of all available entities that the user can choose to follow or unfollow.
+	</Card>
+    <Card title="Seamless Anonymous to Authenticated Flow" icon="link">
+        The `AccountPage` intelligently adapts its UI based on the user's status. For anonymous users, it presents a clear call-to-action to "link" their account, providing a smooth transition to the authentication flow to save their preferences permanently.
+    </Card>
+</CardGrid>