Uninstaller reliability and small fixes

Reliability work across the app, with a few quality-of-life fixes riding along.

• Uninstaller progress and leftover scanning are more reliable.
• Uninstall flows recover more cleanly if the app is closed and reopened mid-process.
• Performance Mode prefers the Atlas power scheme when it is available.
• Optimizer restart prompts clear properly after a reboot.
• Several Optimizer state and modal regressions have been fixed.
• Your PC monitoring pauses while the app is hidden, cutting unnecessary background polling.
• Review submission shows the actual backend error when something goes wrong.
• Status and support links point to the correct pages.
• Unknown RAM manufacturers no longer show awkward fallback text.