0.2.6-alpha4

Changelog

· be8aa63 refactor: split metric runtime from history rows
· 14d812c fix: detach front cache rebuild from caller cancellation
· 00b13d7 fix: report duplicate secret on node updates
· 0b7c567 fix: close server after failed graceful shutdown
· 5907d7d feat: add Linux connection cache helper
· b2eee2c perf: reduce connection cache helper forks
· c645a50 perf: compile Linux connection cache helper
· 451d3fd fix: stabilize metrics integration tests
· f6b8f26 fix: stabilize tests and helper build
· 376b7ec feat: localize node install scripts