Translation memory correctness fixes, a job-cancel crash guard, and a provider-selection validation fix.

What's fixed

• Translation memory correctness. Approved translation memory could silently revert to pending when shared source text was re-translated by another node, and editing a single value on a node deleted translation memory for every other property on that node. Node approval also failed to promote memory for shared text owned by a different node's reference.
• Job cancel/submit crash guard. TranslationJobService.Cancel and MachineConnectorBase.SubmitInternal could throw a NullReferenceException when acting on a job whose Nodes collection wasn't loaded. Cancel now self-heals by reloading nodes from the database.
• Job creation validation. The choose-provider step in job creation didn't validate connector selection before enabling Next, so clicking Next while the connector was still resolving (e.g. a set with no default connector) could save a job with no provider set.
• Log noise. Benign "no translation set applies to this save" cases (invariant doctypes, culture-only saves) no longer log at warning level, and dirty-culture scanning is skipped for doctypes that don't vary by culture.

Other

• Build: bump Jumoo.TranslationManager.Microsoft to 18.1.0, Jumoo.TranslationManager.AI to 18.1.1, and Jumoo.Processing to 18.1.0

Published to NuGet.