https://esc-observability.io/ 2026-04-22 https://esc-observability.io/pdf/ 2026-04-22 https://esc-observability.io/position-paper/ESC_Position_Paper/ 2026-04-22 https://esc-observability.io/strategic-papers/appendix-illustrative-cost-model/ 2026-04-22 https://esc-observability.io/strategic-papers/from-telemetry-inflation-to-decisive-observability/ 2026-04-22 https://esc-observability.io/strategic-papers/strategic-paper-short/ 2026-04-22