refactor: split ci.yml into branch-specific orchestrators, extract version check

- ci.yml: pure dispatch (Feature → ci-feature, Main → ci-main), 18 lines
- ci-feature.yml (new):  load-config → quality-gate
- ci-main.yml (new):     load-config → check-version → quality-gate → docker-build-push
- check-version.yml (new): provider workflow for artifact existence check and version calculation
- docker-build-push.yml (renamed from build_publish-artifact.yml):
  - removed check job, quality-gate block, gatekeeper logic, build-context artifact
  - version passed as input, simplified needs chain (build → push → tag-commit)
  - fixed consumer→provider checkout pattern (.ci/scripts/)

.gitea/workflows/ci-feature.yml

@@ -0,0 +1,20 @@
+name: CI Feature
+on:
+  workflow_call:
+
+jobs:
+  load-config:
+    name: Load gitea-env.conf to pipeline env
+    uses: niko/gitea-ci-library/.gitea/workflows/config-provider.yml@main
+    with:
+      config_path: .gitea/workflows/gitea-env.conf
+
+  quality-gate:
+    name: Quality Gate
+    needs: [load-config]
+    uses: niko/gitea-ci-library/.gitea/workflows/quality-gate.yml@main
+    secrets: inherit
+    with:
+      env_json: ${{ needs.load-config.outputs.env_json }}
+      bats-image: bats/bats:latest
+      cucumber-node-image: node:22