docs: add Agent Canvas visuals from image request #752 - #753

Running Vale across on the following files affected by this PR:

- openhands/usage/agent-canvas/conversations.mdx

Attempting to initialize Vale linter...
No customer vale configuration detected. Using Mintlify's default configuration.
Attempting to run Vale spellcheck...
Vale spellcheck completed successfully.

openhands/usage/agent-canvas/conversations.mdx:
	- 10:164     Did you really mean 'worktree'?
	- 18:169     Did you really mean 'automations'?
	- 34:121     Did you really mean 'scrollbar'?
	- 38:185     Did you really mean 'automations'?
	- 55:102     Did you really mean 'resizable'?
	- 57:133     Did you really mean 'tooltip'?
	- 189:144    Did you really mean 'unarchive'?


Found 7 suggested changes across 1 files in 487.51ms