fix(kernel+tool-shell): abort hanging tool calls without bricking the conversation

kernel: executeToolCall now races tool.execute against the abort signal
via Promise.race; on abort resolves (not rejects) with an "Aborted" result
so the step completes normally → finishReason "aborted" → turn seals
cleanly (done event) → finally clears activeTurns → conversation freed,
next message accepted. run-turn strips tool-call chunks from the assistant
message on abort (keeps text/thinking) and omits tool-result messages to
avoid persisting dangling tool calls that would 400 the provider next turn.

tool-shell: realSpawn spawns detached (own process group); on abort AND
timeout kills the entire group (process.kill(-pgid, SIGKILL)) and resolves
immediately — no child.on("close") dependency, so a grandchild holding the
pipes can't stall the spawn promise or leak.

Also: ORCHESTRATOR.md migrated to dispatch CLI summon mechanism; .skills
summary; bin/sync-env PATH injection; frontend handoff docs.

1453 vitest pass · tsc -b EXIT 0 · biome clean.

0 files changed, 0 insertions, 0 deletions