Fix: UI layout and centering issues in Night Clock and Settings

[knocker-g]

Summary

Fixes layout alignment issues in the Night Clock and dropdown positioning in the Settings screen.

Problem

1. The Night Clock display was not correctly centered on various screen sizes and orientations.
2. Dropdown menus in the Settings screen had incorrect anchoring, leading to potential clipping or misaligned UI elements.

Changes

• Updated alignment logic in NightClockActivity.kt to ensure proper centering.
• Refined dropdown anchoring and menu positioning logic in SettingsScreen.kt.

Testing

• git diff --check: PASS
• F-Droid debug build: SUCCESS
• Play debug build: SUCCESS
• Tests: BLOCKED / NOT EXECUTED
• Manual verification: Verified centering on multiple emulator resolutions. Confirmed dropdown menus appear in the correct positions.