Chore: September 2026 dependency modernization rollup #27

This tracking issue consolidates the complete dependency-modernization pass for NetRatel. The rollup intentionally supersedes open Dependabot dependency PRs only after it is complete and fully validated.

Execution-time Dependabot inventory

• Refreshed on 2026-09-19: no open Dependabot PRs were present.

Any Dependabot PR created or updated during this work will be re-inventoried and added here before it can be considered superseded.

Completion gate before bot PR closure

Individual Dependabot PRs will remain open until all of the following are true:

• The rollup is demonstrably complete.
• Latest-version inventory has been repeated.
• Deprecation migrations are complete.
• Local validation is green.
• Hosted rollup-PR CI is fully green.

The implementation will preserve product behavior and UX, stay on stable .NET 10, retain immutable Action pins, and will not merge, release, tag, deploy, or publish product images.