## Summary
- Replace per-request DNS resolution (variable-based `proxy_pass`) with static `upstream` blocks and `keepalive` connection pools
- Reuses TLS connections through the Tailscale tunnel instead of handshaking per request
- Add `mise run fly-reload` for nginx config reload without full redeploy (re-resolves upstream DNS)
## Trade-off
DNS is resolved at config load, not per-request. If Tailscale Ingress pods get new IPs (restart, reschedule), `mise run fly-reload` is needed. A Grafana alert will be added to detect this.
## Still TODO on this branch
- [ ] Grafana alert for upstream unreachable (triggers fly-reload reminder)
- [ ] Docs pass
- [ ] Deploy from branch and verify latency improvement
- [ ] Changelog fragment
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Reviewed-on: #337
