Replace raw <table> usage with ui_table component

[pachev]

Context

We have a shared MastWeb.Components.UI.Table.ui_table/1 component, but a couple of LiveViews still hand-roll <table> markup from before the component existed.

Sites to migrate

• lib/mast_web/live/settings_live.ex:204 — SSH keys table
• lib/mast_web/live/application_live/view.ex:311 — application updates table

(Skip core_components.ex:370 — that's the Phoenix scaffold's generic <.table>, unrelated.)

Done when

• Both call sites use <.ui_table> with :col slots
• Existing behavior preserved (zebra, sizing, delete actions, etc.)
• mix test + mix format clean

[pachev]

Closed by #30 — both SSH keys table and the application proc table are now migrated to ui_table.