Fix Mongo inventory manifest load order

[azurras]

Summary

• load the immutable domain collection manifest in the same mongosh evaluation unit as the dependent inventory program
• preserve the fixed loopback database and strict inventory-result validation
• add a regression for load-before-use ordering

Root cause

Mongosh processes --eval before --file, so the prior command evaluated the inventory body before DomainCollectionManifest existed.

Validation

• RED: focused contract failed 1/1 against the old seven-argument invocation
• GREEN: focused contract passed 1/1
• PowerShell 7 Operations suite: 91/91
• Windows PowerShell 5.1 + Pester 5.9 Operations suite: 91/91
• both changed files parse on both hosts
• live read-only inventory: complete=true; 14 collections; 52 kinds; 126 indexes; all manifest compliance checks true
• independent review: APPROVED, no Critical/Important findings