Prepare v1.0.0 release

[rimtty]

Summary

• set the QuickPods product, assembly, and file versions to 1.0.0
• finalize the current changelog entries as the 1.0.0 release
• align CI release-candidate versions and the Portable release workflow default with 1.0.0

Release impact

After this PR is merged, the exact Main commit can be used to run the official Portable release workflow and publish tag v1.0.0. The public release will contain only the unsigned portable ZIP and its SHA-256 checksum; the unsigned MSI remains excluded.

Local validation

• locked solution and installer restores passed
• dependency vulnerability audit passed with 0 vulnerable package entries
• repository public-readiness scan passed
• formatting verification passed
• Release build passed with 0 warnings and 0 errors after closing the locally running development build
• Foundation tests: 149 passed; all other suites passed except the known environment-sensitive local USER-handle assertion
• local QuickPods-1.0.0-win-x64.zip generated successfully
• portable payload version/layout/unsigned state validated
• generated ZIP SHA-256 matched SHA256SUMS.txt