[AlexAndBear]

Description

• Quota rounding: custom quotas like 4.1 GB are rounded to whole bytes, so the server no longer rejects 4099999999.9999995 with 400.
• Validation: values below one byte (e.g. 0) show an error instead of silently becoming "No restriction".

Related Issue

• Fixes Custom quotas like 4.1 or 8.2 GB fail with HTTP 400 #3673

How Has This Been Tested?

• test environment: unit tests (Vitest)
• test case 1: createOption('4.1') returns 4100000000
• test case 2: createOption('0') returns an option with an error

Types of changes

• Bugfix
• Enhancement (a change that doesn't break existing code or deployments)
• Breaking change (a modification that affects current functionality)
• Technical debt (addressing code that needs refactoring or improvements)
• Tests (adding or improving tests)
• Documentation (updates or additions to documentation)
• Maintenance (like dependency updates or tooling adjustments)