refactor(#285): extract section composables from SettingsScreen and ChatScreen (#358)
* refactor(#285): extract ConnectionSection from SettingsScreen
* refactor(#285): extract TestResultCard, SaveIndicator, SettingsActionButtons
* refactor(#285): extract BehaviorSection from SettingsScreen
* refactor(#285): extract AppearanceSection from SettingsScreen
* refactor(#285): extract ChatSection from SettingsScreen
* refactor(#285): extract NavBarSection from SettingsScreen
* refactor(#285): extract AboutSection from SettingsScreen
* refactor(#285): extract ChatLifecycleEffects from ChatScreen
* refactor(#285): extract ChatTopBanner from ChatScreen
* refactor(#285): extract ChatMessageList, ChatLoadingOverlay, ChatScrollToBottomFab
* fix(#285): use fully-qualified ButtonDefaults, BoxScope receiver for ChatScrollToBottomFab
* fix(#285): add BoxScope import
* fix(#285): pass isLoading as param instead of accessing StateFlow.value
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Co-authored-by: M57 <hy4ri@users.noreply.github.com>