feat(vmware): add vm_platform_from_annotation_relation config option

[dirtycache]

Problem

Appliance-style VMs — network and security virtual appliances, load balancers, firewalls, etc. — typically run on a modified Linux base. vSphere correctly identifies the underlying kernel as CentOS, Ubuntu, or similar, and that is what gets synced to NetBox as the VM's platform. The actual product identity is lost.

These VMs often carry product-identifying text in their vCenter annotation (Notes field), which is already synced to NetBox as the comments field. There is currently no way to use that annotation content to influence platform assignment.

This is a gap that affects any operator running virtual appliances alongside general-purpose Linux VMs: both classes end up with the same platform name in NetBox, making it impossible to filter or report on them by platform.

Related issues: #429, #495.

Solution

Adds a new optional config option vm_platform_from_annotation_relation to the VMware source handler, following the same key = value regex pattern as the existing vm_platform_relation.

The key difference is what is matched: instead of matching the vSphere-reported guest OS name, patterns are matched against the full vCenter annotation text using re.search with re.DOTALL. This means:

• patterns match anywhere in a multi-line annotation without anchoring
• newlines are transparently handled — no special flags needed in the config
• the option takes priority over vm_platform_relation when both would match

The annotation is now always read from vCenter regardless of the skip_vm_comments setting, so platform detection works correctly even when comment syncing is disabled. If skip_vm_comments is true, the annotation is used only for platform detection and is not written to comments.

Changes

• module/sources/vmware/config.py: registers the new ConfigOption in the relations group with its own validator that compiles patterns with re.DOTALL
• module/sources/vmware/connection.py: reads annotation unconditionally, applies annotation-based platform override after vm_platform_relation, guards comments assignment behind skip_vm_comments
• settings-example.ini: documents the new option with a concrete example

Config example

; Map F5 BIG-IP LTM Virtual Edition VMs to the TMOS platform regardless of
; what vSphere reports as the guest OS
vm_platform_from_annotation_relation = BIG-IP Local Traffic Manager Virtual Edition.*F5 = TMOS

; Multiple mappings are comma-separated, same as other relation options
; vm_platform_from_annotation_relation = ProductA.*Vendor = PlatformA, ProductB.*Vendor = PlatformB

Backwards compatibility

Fully backwards compatible. If vm_platform_from_annotation_relation is not set, the new code path is a no-op (empty list iteration). No existing behaviour changes.