fix: keep readiness finding verbs inside the pane

[AnsoCode]

Summary

• On a 1280-wide window the Fleet Readiness findings table was wider than its pane, so the resolving verb (Capture recovery point, Start stack, and the rest) sat past a horizontal scroll.
• Until the window is wide enough for every column, Stack and Domain are named on the finding, and Node, State, and Action take a share of the pane so the verb and Dismiss stay visible.
• On a wide window, Stack and Domain return as their own columns.

Test plan

• Open Fleet, then Readiness, at 1280. Confirm the verb and Dismiss are on screen with no horizontal scroll.
• Widen the window until Stack and Domain reappear, and confirm the verbs still fit.
• Narrow the desktop pane with the sidebar open and confirm the verbs stay in the pane.
• Frontend typecheck is clean, and the readiness findings tests pass (66).