Enhancement: Custom Fonts & Text Alignment

[Pranav00076]

Description:
Text blocks and sticky notes only use the default font. We should allow basic text formatting.

How to Implement:

1. Font Loading: Import a few Google Fonts via CSS or WebFontLoader.
2. Fabric Properties: Update the fontFamily and textAlign properties on the selected fabric.IText or fabric.Textbox object.
3. UI Updates: Add a font-family dropdown menu and alignment toggle buttons (Left/Center/Right) to the text properties toolbar.
4. Sync: Add these properties to the Yjs sync payload for text objects.