Tag and publish v1.0.0 release

[kcenon]

What

Create the v1.0.0 git tag and GitHub release after all v1.0 preparation sub-issues are complete.

Part of #670

Why

• Final step in the v1.0 release process
• Provides a stable, versioned snapshot for downstream consumers
• Enables find_package(thread_system 1.0) and vcpkg version pinning

When

Dependencies (must all be closed first)

• Result migration sub-issue
• API freeze audit sub-issue
• Documentation/version bump sub-issue

How

Technical Approach

1. Verify all v1.0 sub-issues are closed
2. Verify CI passes on main branch
3. Create annotated tag: git tag -a v1.0.0 -m "Release v1.0.0: stable API"
4. Push tag: git push origin v1.0.0
5. Create GitHub release with release notes from CHANGELOG

Acceptance Criteria

• All v1.0 sub-issues closed
• CI green on main
• Git tag v1.0.0 created and pushed
• GitHub release published with release notes
• find_package(thread_system 1.0) works from tag

[kcenon]

Implementation Update

Field	Value
Release PR	#679
Tag	v1.0.0
Release	https://github.com/kcenon/thread_system/releases/tag/v1.0.0
Status	Complete

Summary

All v1.0 sub-issues verified closed. CI passed (28 checks). Release PR merged to main, annotated tag v1.0.0 created and pushed, GitHub Release published with full release notes.