Merge pull request 'ci: publish one tag per build, YYYY-MM-DD-HHMM' (#24) from claude/date-image-tag into main

Reviewed-on: #24

.woodpecker/release.yml

@@ -19,14 +19,14 @@ steps:
       # The repo owner is an organisation; the registry login is the bot in its Bots team.
       - AUTH=$(printf "%s" "claude-bot:$GITEA_TOKEN" | base64 -w0)
       - printf '{"auths":{"%s":{"auth":"%s"}}}' "$$REGISTRY" "$AUTH" > /kaniko/.docker/config.json
-      - BUILD_TAG="build.$(date +%s)"
+      # One tag per build, YYYY-MM-DD-HHMM (UTC): the homelab Flux
+      # ImagePolicy rolls out the newest, and Gitea's cleanup rule counts
+      # every tag as a version, so extra tags would push this one out.
+      - TAG="$(date +%Y-%m-%d-%H%M)"
       - >-
         /kaniko/executor
         --context=.
         --dockerfile=Dockerfile
-        --destination=$$IMAGE:${CI_COMMIT_SHA}
-        --destination=$$IMAGE:${CI_COMMIT_SHA:0:7}
-        --destination=$$IMAGE:$${BUILD_TAG}
-        --destination=$$IMAGE:main
+        --destination=$$IMAGE:$${TAG}
         --snapshot-mode=redo
         --use-new-run