feat: migrate workflows to kcl-ci standard

- Add .forgejo/kcl-ci/ with kcl.mod, main.k, Taskfile.yaml
- claude.yml: use claude.k module (fixes #comment YAML validation error,
  removes duplicate pull_request_comment trigger)
- ci.yml: add paths-ignore for kcl-ci paths, named jobs for check constants
- test-action.yml: regenerated from KCL (functionally identical)
- upstream-sync.yml: regenerated from KCL (functionally identical)
- kcl-ci-build.yml: new auto-regeneration workflow (waits for CI checks)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.forgejo/kcl-ci/kcl.mod.lock

@@ -0,0 +1,7 @@
+[dependencies]
+  [dependencies.kcl-ci]
+    name = "kcl-ci"
+    full_name = "kcl-ci_0.0.1"
+    version = "0.0.1"
+    url = "https://git.wxs.ro/actions/kcl-ci"
+    git_tag = "v1.34.3"