Map Provider and API Key changes no longer require restart

[dpaulat]

No description provided.

[Copilot]

Pull request overview

This PR enables map provider and API key changes to take effect immediately without requiring a restart. It achieves this by upgrading the SettingsVariable<T> signal to carry ChangedEvent<T> (with old/new values), adding a ResetMap/ConfigureMapSettings mechanism to the map layer, and wiring provider/key changes to reactive signal handlers.

Changes:

• SettingsVariable<T> signals now carry a ChangedEvent<T>{oldValue_, newValue_} struct, and ConnectChanged/ConnectStaged virtual methods are added to SettingsVariableBase for type-erased signal connection
• map_widget.cpp gains ResetMap() and ResolveMapStyleName() to handle dynamic provider and API key changes, and consolidates signal connections into connections_ vector
• main_window.cpp wires map_provider and custom style changes to PopulateMapStyles/ConfigureMapStyles; OS name is added to the user agent and startup log

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
settings_variable_base.hpp/cpp	Removes changed_signal()/staged_signal() from base class; adds ConnectChanged/ConnectStaged pure virtual methods
settings_variable.hpp/cpp	Adds ChangedEvent<T> struct and moves typed signals here; updates all mutation paths to pass old/new values
settings_category.cpp	Updates ConnectVariable to use new ConnectChanged/ConnectStaged helpers
map_widget.hpp/cpp	Adds SetMapStyle force parameter; adds ResetMap/ResolveMapStyleName; connects provider/API key changed signals
map_provider.hpp/cpp	Extracts ConfigureMapSettings() from MainWindowImpl
main_window.cpp	Dynamically responds to provider changes; uses QSignalBlocker for combobox updates; connects custom style signals
marker_settings_widget.cpp, overlay_layer.cpp	Updates lambda signatures to auto&&... to accept new signal arguments
placefile_manager.cpp	Adds URL to error messages for placefile load failures
main.cpp	Adds OS name to log output and user agent

[Copilot]

@dpaulat I've opened a new pull request, #597, to work on those changes. Once the pull request is ready, I'll request review from you.

[github-actions]

clang-tidy made some suggestions

[github-actions]

clang-tidy made some suggestions