Removes .woodpecker.yml and replaces the tag-triggered image publish flow
with a local-build-and-push script (release-image.sh).
Why: the CI added two indirections (Woodpecker dashboard, Codeberg secrets
config) that aren't worth the cost for a single-developer release flow.
When the previous release didn't show up in the package registry, "did
the release happen?" required checking three places (the git tag, the
CI dashboard, the registry); with local builds, success or failure is
visible in the developer's terminal immediately.
The cascade behavior is preserved: `sh release-image.sh 0.0.3` publishes
:0.0.3 :stable :beta :alpha just like the .woodpecker.yml job did. Beta
and alpha channels work identically (`sh release-image.sh 0.0.3-beta.1
beta` → :0.0.3-beta.1 :beta :alpha).
The git-tag convention stays (`zddc-server-vX.Y.Z`); now you tag *and*
run the script as two coordinated steps. AGENTS.md "Release tagging" and
zddc/README.md "Release Tagging" / "Container image" updated to reflect
the new flow. No code change in the binary.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
