Docs: add discovery network object operator examples

[BadgerOps]

Follow-up to #187 and PR #188.

Summary

Expand discovery documentation with practical operator examples for network objects, hierarchy, import, and duplicate handling.

Why

PR #188 documents the vocabulary and API basics. Operators will need concrete examples that map common cloud layouts to CloudPAM behavior.

Scope

• Add examples for VPC inside pool, subnet with missing VPC parent, duplicate VPC CIDR across AWS accounts, EIP as account/region object, pool-per-account layout, and pool-per-region layout.
• Include example API responses or screenshots where useful.
• Explain when VPCs/subnets/EIPs should remain discovered-only, link-only, imported network objects, or allocated blocks.

Acceptance Criteria

• Admin docs include the main operator scenarios from Harden discovery import, hierarchy, and conflict handling for cloud network objects #187.
• Examples match current API/UI behavior.
• Documentation names any current limitations and points to follow-up issues.