feat(web): merge network quality detail into server detail tabs

[ZingerLittleBee]

Summary

• Move the server detail tab bar to the top of the page (directly under the page header) and sink the cost/traffic/uptime overview blocks into the Metrics tab, so tab switching is prominent while the default view stays unchanged.
• Add a Network tab hosting the full network quality experience (latency chart, target cards, stats, anomalies, traceroute, target management, CSV export) extracted from the standalone /network/$serverId page.
• /network/$serverId now redirects to /servers/$id?tab=network, mapping the legacy hour-based range values (1/6/24/168/720) to metrics-style keys (1h/…/30d). Network overview cards deep-link to the tab.
• The Network tab shares the server detail range search param, so the selected time window carries across tabs (e.g. spot an anomaly in Metrics at 7d, switch to Network still at 7d).
• In-flight traceroute run state (request id, latest full-state stream frame, selection) is hoisted into a per-server zustand store so switching tabs and back resumes the live progress view — each traceroute_update WS frame carries the full hop state, so resume needs no reconnect logic.

Public status pages

• The public server detail gains a redacted Network tab (summary + anomalies only), gated on the show_network toggle, with a ?tab= search param for deep links.
• /status/network/$serverId redirects into the tab when show_server_detail is enabled, and keeps rendering standalone as a fallback for status pages configured with show_server_detail=false + show_network=true — both config toggles keep their existing semantics. Rationale recorded in docs/adr/0001-network-detail-as-server-tab.md.

Testing

• bun run typecheck, bun x ultracite check, and bun run test (668 tests) all pass.
• New tests: redirect + range mapping for the legacy route; NetworkTab toolbar/localization/manage-targets dialog.
• Visually verified in the browser against production data (prod-proxy): tab bar placement, Metrics tab overview blocks, Network tab full experience and empty state, legacy-route redirect, public-side conditional redirect, tab clicks, and range persistence across tabs.