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The RHS could be triggered by a button in the Channel header Bar OR a Quick Link (similar to Github plugin) and then provide access to confluence functionality.
Alternatively, slash commands could also expose the RHS. Keep in mind the RHS has the capability of being expanded to fill more of the screen, giving some room to potentially render Confluence pages in the RHS (they have a specific API endpoint for extracting and rendering content in different view formats, we would use one of those):
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Ideas for Interactive Elements:
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