Feature: feat/telemetry-prod-grading to dev

[github-actions]

Automated PR tracking changes from feat/telemetry-prod-grading into dev.

---

Note

Medium Risk
Adds read-heavy aggregate queries on the metrics scrape path and admin polling (60s/15s caches mitigate); judging-idle alerting depends on correct gauge semantics during live events.

Overview
Adds database-backed hackathon telemetry for live editions (open, closed, in_progress): new dsgt_hackathon_* Prometheus gauges, a Grafana row, docs, and a HackathonJudgingIdle alert when judging is on with tables assigned but zero scores for 30 minutes.

readLiveHackathons centralizes the counts (participants by status, projects, Eastern-midnight badge scans, judging tables/votes) and feeds both refreshDbGauges (with gauge reset so completed editions drop off) and a cached admin.hackathonLive tRPC query. Membership/payment gauge refresh is rewritten from raw SQL to Drizzle; plan mix still comes from payment metadata parsing.

Admin analytics splits today’s turnout into badgeScansToday (hackathon QR) vs doorCheckinsToday (club events), keeps checkinsToday as the sum for older callers, and the analytics page adds a Live hackathon section aligned with metrics.

ClickHouse gets hackathon tables (02-hackathon.sql) and export:clickhouse exports registrations, projects, scans, and votes (schema ensured on existing volumes).

^{Reviewed by Cursor Bugbot for commit eee1f4f. Bugbot is set up for automated code reviews on this repo. Configure here.}