forgepulse: GitHub links on detail pages, gghstats issues checked

forgepulse’s repository detail page now links its title, top referrers, and popular paths straight to GitHub (paths always, referrers only when they look like real hostnames), and the JSONL export filename embeds a UTC timestamp so re-downloads stop silently overwriting the previous file. A cross-check against the issues opened on hrodrig/gghstats found that three of them applied to forgepulse too — the export filename, the stats-panel jargon, and the rank column header — and were fixed here; the locale-formatting issue does not apply in the same shape yet.