feat(agent): add Swedish Desktop Agent localization - #1984

Implementation notes:

• Adds Resources.sv.resx as a standard .NET satellite resource, following the existing French resource pattern.
• Contains the same 14 visible Desktop Agent keys as the neutral resource; no source strings, generated code, or runtime behavior change.
• XML syntax was validated with the available parser, key parity found 14/14 keys with no extras or empty values, and git diff --check passes.
• The local environment does not include the .NET SDK, so resource compilation is intentionally left to the repository CI.
• No breaking changes or migration steps.

Installer localization update:

• Adds a Swedish sv-se WiX localization resource for the Agent installer and registers it as an embedded installer resource.
• The resource has 72/72 current English installer keys, including Agent Tunnel DNS/CIDR enrollment, PowerShell Universal endpoint/token configuration, UAC, installation, repair and removal flows.
• XML parsing, exact key parity, MSI variable/format-token parity, and git diff --check pass locally.
• The .NET/Wix build remains delegated to repository CI because the local environment has no .NET SDK.

Superseded by #2031, which converts the installer strings to the JSON/T4 pipeline, adds the firewall strings WiX needs for sv-SE, and wires the build scripts. Thank you for the translation, Daniel; it is credited with Co-authored-by.

Hi Daniel Nylander (@yeager)! Thanks a lot for the contribution. I'm most happy to accept new localizations.

Actually there were a few problems with the PR as it stands

1. The WiX .xlt files are "hand" edited; actually we have a localization build system that generates these from strings held in .json files. So the edits would have been lost the next time someone ran that re-regeneration
2. Multi language .msi are built as transforms (one per language) and then merged into the final .msi at the end. At runtime the system or user selects which language transform to use. So, the build system as a whole needs awareness of a new installer language.

This is all fairly byzantine knowledge so what I'm doing is:

1. Making a new PR incorporating your localizations, and address the items above in one-shot
2. Adding some Agent skills and documentation so that future implementers understand what needs to be done to localize an installer

Otherwise, as I said, thanks a lot for the contribution! I'll close this PR once #2031 is merged, but I did credit you as co-author on that.

Superceded by #2031