Refactor Pi Herdr orchestration

[RestartDK]

Summary

• replace the Pi Herdr CLI subprocess adapter with a typed raw Unix-socket client
• generate protocol request/response types from Herdr's canonical JSON Schema and add freshness/type checks
• move background tests, builds, servers, and watchers into dedicated unfocused Herdr tabs; prevent splitting Pi's interactive tab
• refresh Herdr's managed Pi, Claude, Codex, and OpenCode lifecycle integrations and remove the duplicate Pi state extension
• update the Herdr flake input and clarify that config workflows should invoke traitor from PATH

Validation

• traitor update herdr
• clean-worktree traitor check
• generated protocol types checked against Herdr 0.7.5 (f67803f)
• npm run typecheck
• npm run check-generated
• npm audit --omit=dev (0 vulnerabilities)
• managed integration status: Pi v7, Claude v7, Codex v6, OpenCode v9
• Pi RPC extension load
• live socket list/read/split/send/wait/close calls
• JSON, shell, and JavaScript syntax checks