chore: bump packages with unreleased changes since last publish

- pi-subagent 0.8.0 -> 0.9.0 (breaking: required task profiles; plus
  Anthropic top-level combinator fix, worktree GC, pi 0.84 compat)
- pi-sentinel 0.1.0 -> 0.2.0 (native PR monitoring, wakeup cost fixes)
- pi-ask-user, pi-dashboard, pi-github, pi-linear, pi-notion, pi-slack
  0.1.0 -> 0.1.1 (fix commits since publish)
- pi-workflows 0.1.0 -> 0.1.1 (track pi-subagent ^0.9.0)
- pi-subagent CHANGELOG: cut Unreleased as 0.9.0