R1:1858d2aa6679

Make Differential timeline aware of ghostly inlines

Summary:
Ref T7447. Ref T7870.

When a ghostly inline appears on the page, the timeline isn't currently aware that it's present, so it links elsewhere.

Instead, apply adjustments before rendering the timeline.

Ref T5030. This makes the behaviors in T5030 irrelevant most of the time.

Test Plan:
Before:

{F378106}

After:

- Inlines visible on page are linked directly.
- Inlines which we can't port (e.g., on files not present on current page) are…