Update dependencies, logos, banner, and enhance UI with tests

[HarshPanchal01]

Summary of Changes

This pull request updates branding and icons throughout the application, improves platform-specific logo handling, and makes several UI and accessibility adjustments. The most significant changes include replacing old icons and logos with new, platform-specific assets, updating the logic for displaying the correct logo based on OS and theme, and refining the appearance and accessibility of toggle switches. There are also minor improvements to the finance API integration and a cleanup of font usage.

Branding and Asset Updates

• Replaced previous icons and logos (icon.svg, logo.png, icon.png) with new, platform-specific assets (onefinance_icon_win_light.png, onefinance_icon_mac_light.png, etc.) in both the build configuration (electron-builder.json) and throughout the app for Windows, macOS, and Linux. [1] [2] [3] [4]
• Updated Vue components (Sidebar.vue, SettingsView.vue) to use new lockup images that adapt to platform (Windows/macOS) and theme (light/dark) via computed logic, replacing static imports and simplifying the logo display. [1] [2] [3] [4] [5]

UI and Accessibility Improvements

• Refined the appearance of toggle switches across multiple components to improve dark mode support and visual clarity by adjusting the background color classes. [1] [2] [3] [4] [5] [6] [7] [8]
• Simplified and modernized the header layout in Sidebar.vue and SettingsView.vue for a cleaner look, removing redundant containers and text. [1] [2] [3]

Finance API Integration

• Updated the Yahoo Finance integration to use the new chart() method instead of the deprecated historical() for fetching historical prices, improving reliability and future-proofing the code. [1] [2]

Styling and Fonts

• Removed the external Inter font import and switched to using Tailwind's default font-sans utility for better performance and consistency. [1] [2]