Context

Part of #639. Derived from the 2026-06-13 analysis: common declares 1.0.0 in VERSION/vcpkg.json/CHANGELOG/README but has NO v1.0.0 git tag (highest tag v0.2.0); develop is 21 commits ahead of main. README's FetchContent GIT_TAG v1.0.0 is therefore a dangling reference, and every downstream v1.0 pin is unbackable.

Why keystone

common is the sole Tier-0 hard dependency of all other systems. Until its real tag exists, logger/monitoring/network/pacs cannot pin to a real common v1.0. This is the single highest-leverage action in the ecosystem v1.0 cascade.

Preconditions (apply P3 to common itself: all contract fixes land before the tag)

• get_category_name classifier fix landed in develop
• Error-code registry contract gate landed and green
• No remaining common-side public-surface changes pending

Scope / Acceptance Criteria

• Release-merge develop -> main per docs/RELEASING.md
• Cut an annotated, GPG/SSH-signed v1.0.0 tag on main; enable tag protection so v* cannot be moved
• gh release create with notes; verify vcpkg portfile SHA512 against the published archive
• "tag-reality" gate: assert git rev-parse v1.0.0 resolves AND equals the release-merge HEAD AND vcpkg.json / VERSION / CHANGELOG / vcpkg-registry baseline all agree
• Update Track ecosystem-wide v1.0 API stabilization readiness #639