Speed up the timeline charts

The timeline chart above runs, logs, and units tables used to show a blank band while the page loaded, then pop in with a delay.

• Added chart bars directly into the initial page response, so the timeline is visible the moment the page appears instead of after a blank pause
• Improved loading placeholders to match the chart and table layout exactly, removing visible jumps when content arrives
• Fixed charts disappearing into a loading state on every filter change; the previous chart now stays visible while new data loads