Gate CityView behind own/spy/spectator and fix spectator city select

[Fanfblrik]

Summary

• Follow-up to the review on closed allow spectator to select city #15376 and the tryGetCityView work in RFC: Views #15280. Replaces Gate CityView behind own/spy/spectator and fix spectator city select #15386 (rebased onto current master after selectedGameView / FoW unification).
• CityView can only be constructed when the viewer owns the city, has a set-up spy there, or is a spectator (require(canSeeInternals())). UI opens CityScreen through tryGetCityView / GameView.tryGetCityView, so an unauthorized CityScreen cannot be created.
• Spectator city selection on the map (first click / tile click, like units) uses ForeignCityView.canSelectOnMap() instead of an isSpectator() special-case in CityButton. Spies still cannot select a foreign city as the WorldScreen attacker (bombard), only open it via tryGetCityView.

Test plan

• As spectator, first-click a city button: city is selected in the unit table (name, strength, bombard stats)
• Second-click / right-click: CityScreen opens
• Click the city tile (not the button): same selection as own-civ click-to-select
• As a normal player, own cities still select and open as before
• Foreign city without a set-up spy: no CityScreen, diplomacy/info popup as before
• Set-up spy: View / second click opens CityScreen; first click does not select that city for bombard
• Notification / overview / capital hotkey / improvement picker city links still open CityScreen for allowed cities only

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[Fanfblrik]

Superseded by a rebased PR after master CityScreen/TileView migration conflicts: will link the new PR once created.

Made with Cursor

[Fanfblrik]

Superseded by #15389 (rebased onto current master after CityScreen/TileView migration conflicts).

[Fanfblrik]

Closed in favor of #15389.