Config editor saves empty fields as empty strings instead of null

[xingjianll]

Bug

When a config field is left blank in the UI config editor, it saves as "" (empty string) in graph.json instead of null or omitting the key. This causes from_args to pass the empty string to __init__, which fails when the parameter expects a numeric type.

Example: VRChatVideo has fps: int = 30. Leaving it blank saves "fps": "", which causes:

TypeError: unsupported operand type(s) for /: 'float' and 'str'

Expected behavior

• Empty config fields should be saved as null in JSON, or the key should be omitted
• from_args should skip null/empty-string values and let the __init__ default apply

Affected code

• Frontend: config editor input handling (saves "" instead of null)
• Backend: src/core/component.py from_args() — no type coercion or empty-string handling