feat(desktop): add settings schema and integrate settings service

[Red-Asuka]

This pull request includes several changes that primarily focus on replacing the posts schema with a new settings schema and integrating it throughout the codebase. Additionally, it introduces a new PlatformType to differentiate between desktop and web platforms. Below are the most important changes:

Schema and Database Changes:

• Replaced the posts schema with a new settings schema in the database configuration files (apps/desktop/src/database/db.main.ts, apps/desktop/src/database/db.renderer.ts). [1] [2] [3]
• Removed the posts schema file and added a new settings schema file with various settings attributes (apps/desktop/src/database/schemas/posts.ts, apps/desktop/src/database/schemas/settings.ts). [1] [2]

Service and Configuration Updates:

• Introduced useSettingsService to manage settings in the database and update the store (apps/desktop/src/database/services/SettingsService.ts).
• Updated the createWindow function to use settings from the database for window dimensions and theme (apps/desktop/src/main/index.ts). [1] [2] [3]

Platform Type Integration:

• Added a new PlatformType type to differentiate between desktop and web platforms (packages/types/base.ts).
• Updated various files to provide the PlatformType and conditionally render settings based on the platform (apps/desktop/src/renderer/src/main.ts, apps/web/src/main.ts, packages/ui/src/components/SettingsView.vue). [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

Miscellaneous:

• Added a new alias for the database directory in the Vite config and tsconfig.web.json files (apps/desktop/electron.vite.config.ts, apps/desktop/tsconfig.web.json). [1] [2]
• Updated imports and usage of settings store in various files to reflect the new structure (apps/web/src/database/services/SettingsService.ts, packages/ui/src/stores/useSettingsStore.ts). [1] [2]