Add inline comments for plans

[marcio-absmartly]

The biggest contribution of VK for my AI workflow, after the automatic management of worktrees, was the inline reviews interface, though it has it's issues, it really improved the precision of my reviews.
Google's antigravity now has this for the plans as well: you select a bit of text in the plan, and then you can comment on it on a popup, which again, really increases the precision of any corrections I need done to the plan.
I think it and would be a great addition to VK.

[stunningpixels]

I like this idea!