fix filepath text wrapping in diff panel

[adboio]

problem

i fumbled this one :)

the filepaths in the diff review panel are like /path/to/**file.tsx**

but the bold part i guess is not inline with the rest, so when it's too long, it goes like this:

solution

let's fix the wrapping -- but i don't think normal wrapping will look very good here

instead, i think we should get ✨ fancy ✨ with it and use pretext to middle-truncate long file names 🤓

something like this:

frontend/.../marketing_analytics_config/ColumnUnmappedDescriber.tsx

and probably would be best to ensure we don't truncate mid-dir-name, so the truncation always happens between slashes (/.../) instead of something like src/sc....nfig/the-file.tsx

i think this approach also gives us the ability to show the filename in a tooltip on hover, but only if it got truncated (i hate tooltips, so the less, the better lol)

acceptance criteria

filenames in the diff panel...

• no longer wrap poorly
• are middle-truncated, always breaking on slashes
• still keep the filename visually distinct from the path
• show full filepath in a tooltip on hover, only when they are truncated

[reverb256]

I'm looking into this and plan to submit a PR shortly. Middle-truncation with pretext + slash-aware truncation + conditional tooltip sounds great.