Fix post-merge playthrough regressions

[wan0net]

Summary

• prevent the opening-movie skip key from activating the title menu or leaking across game resets
• suppress browser-native handling for game function-key shortcuts
• centre loaded games on a human unit or city rather than an unseen AI unit
• separate the Foreign Advisor empty state from its Close button

Verification

• public runtime allow-list passed
• production build passed
• 273/273 Playwright tests passed
• human playthrough verified setup, capital founding, city production, options, save/load, research discovery, diplomacy, spaceship, and Civilopedia