🪪 style: Improve a11y of Agent Cards in Marketplace (#10957)

* style: AgentCard and AgentGrid UI with improved layout and accessibility

- Updated AgentCard component to improve layout, including flexbox adjustments for better responsiveness and spacing.
- Added aria-label for agent description to enhance accessibility.
- Introduced a new translation key for agent description in the localization file.
- Modified AgentGrid to include horizontal margins for better alignment on various screen sizes.

* style: Update AgentCard description line clamp for improved readability

- Increased the line clamp for agent descriptions in the AgentCard component from 3 to 5 lines, enhancing the display of longer descriptions while maintaining a clean layout.

* feat: Integrate Agent Detail Dialog in AgentCard Component

- Enhanced the AgentCard component to include an OGDialog for displaying detailed agent information.
- Introduced AgentDetailContent to manage the content of the dialog, allowing users to view agent details and initiate chats directly from the card.
- Updated AgentGrid to utilize the new onSelect prop for agent selection, improving the interaction flow.
- Removed deprecated code related to agent detail handling in the Marketplace component for cleaner implementation.

* ci: Enhance AgentCard and Accessibility Tests with Improved Mocks and Keyboard Interaction

- Updated AgentCard tests to utilize the new onSelect prop for better interaction handling.
- Introduced comprehensive mocks for hooks and components to streamline testing and avoid testing internal implementations.
- Improved accessibility tests by ensuring keyboard interactions are properly handled and do not throw errors.
- Enhanced the overall structure of tests to support better readability and maintainability.

client/src/locales/en/translation.json

@@ -34,6 +34,7 @@
   "com_agents_copy_link": "Copy Link",
   "com_agents_create_error": "There was an error creating your agent.",
   "com_agents_created_by": "by",
+  "com_agents_description_card": "Description: {{description}}",
   "com_agents_description_placeholder": "Optional: Describe your Agent here",
   "com_agents_empty_state_heading": "No agents found",
   "com_agents_enable_file_search": "Enable File Search",