Add daily activity report agentic workflow

Creates a scheduled workflow that runs daily on weekdays to summarize
recent repository activity (commits, PRs, issues) and delivers it as
a GitHub issue.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Dedac

.gitattributes

@@ -0,0 +1 @@
+.github/workflows/*.lock.yml linguist-generated=true merge=ours