Agents "RHS" view

[crspeller]

Summary

This PR adds mobile support for the Agents RHS (right-hand side) interface, including:

• Agents button in sidebar: New menu option to access agents functionality
• Agent threads list screen: View and manage all agent conversations in one place
• Agent chat screen: Dedicated interface for chatting with AI agents
• Bot selector bottom sheet: Choose between multiple agents with avatar display, replacing the previous click-and-cycle behavior
• Auto-navigation: Automatically navigate to thread view after sending a message to an agent

This implementation provides a native mobile experience for the agents feature, allowing users to interact with AI agents directly from the mobile app.

Original PR that added post and streaming support: #9317

Ticket Link

https://mattermost.atlassian.net/browse/MM-66762

Device Information

This PR was tested on: Pixel 7 android 16

Screenshots

Release Note

Added mobile support for AI agents including a dedicated agents menu, agent chat interface, threads list view, and bot selector with profile pictures.

[github-actions]

Coverage Comparison Report

Generated on December 12, 2025 at 17:48:53 UTC

+-----------------+------------+------------+-----------+
| Metric          | Main       | This PR    | Diff      |
+-----------------+------------+------------+-----------+
| Lines           |     86.18% |     86.12% |    -0.06% |
| Statements      |     86.06% |     86.00% |    -0.06% |
| Branches        |     72.61% |     72.61% |     0.00% |
| Functions       |     85.40% |     85.33% |    -0.07% |
+-----------------+------------+------------+-----------+
| Total           |     82.56% |     82.51% |    -0.05% |
+-----------------+------------+------------+-----------+