The template catalog drawer incorrectly enforces the root disk minimum size (e.g. 60 GiB) on the CD-ROM source when the CD source type is HTTP or Upload.

The CD-ROM disk size input shares the same SelectSource component as the root disk, and it always computes the minimum from the root disk template size via getRootDiskStorageRequests. This causes a "Size cannot be less than 60 GiB" validation error on the CD-ROM, which should not have this constraint since it is independent from the root disk.

Steps to reproduce:
1. Open the template catalog drawer
2. Enable the Boot CD checkbox
3. Select HTTP or Upload as the CD source
4. Observe the disk size input shows "Size cannot be less than 60 GiB"

Expected: The CD-ROM source should not enforce the root disk's minimum size.
Actual: The CD-ROM inherits the root disk minimum (e.g. 60 GiB) and shows a validation error.