P8 — Continuous profiling (Pyroscope)

[gangster]

Part of the observability epic #102 (Track D). Full design: docs/plans/102-observability-stack.md.

Scope. Pyroscope store (S3 + IRSA, auth_enabled + per-tenant limits, high_availability toggle) + Alloy/SDK profiling; Grafana traces ↔ profiles link (flame graph from a slow span).

Verify. CPU/heap flame graphs for the hub’s own components; jump from a trace to its profile.

Dependency / ordering. Needs P3.

[gangster]

Done — P8 continuous profiling shipped in #637 (Pyroscope store + eBPF collection on both clusters, 51+ services profiled, tracesToProfilesV2 correlation, preprod profiling spoke). LGTM+P complete. (The PR's Closes-#587 didn't auto-fire on merge.)