v0.3.9

Changed

• PluginManifest narrows to 3 fields (name, post_round_hooks, cooperative_stop) — dropped 6 zero-producer hook seams, the DirtyHandler seam (dirty-tree resolution is now plain core), the sandbox subsystem, and the owned-paths registry, all with zero real producers.
• sigterm_cooperative: bool is now typed cooperative_stop: Literal["SIGTERM", "SIGINT"] | None: claude now drains on SIGINT (SIGTERM abandoned its turn), gemini/pi stay on SIGTERM; the hard-wall kill path stays SIGTERM-first regardless.
• The claude builtin plugin's manifest/entry-point name changed from claude_rate_limit to claude (agent-runner migrate flags any [plugins] disable entry still naming the old value).
• peek --json schema bumps to 2.6.

Removed

• [plugins] sandbox/pin/spawn_override_allow/raw config keys and [runtime]/[phases.<name>] disable_pre_round_hooks — run agent-runner migrate before upgrading.