Merge remote-tracking branch 'origin/codex/enforce-tool-cancellation' into worktree/explicit-turn-signal

# Conflicts:
#	docs/architecture.md
#	docs/cordis-catalog/events.md
#	docs/event-producer-consumer.md
#	docs/persistence-catalog.md
#	examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl
#	examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/stdout.expected.jsonl
#	packages/cordis/tool-cordis/src/api-catalog.ts
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/src/loop.ts
#	packages/core/agent/README.md
#	packages/examples/cli-demo/src/cli.ts
#	packages/ui/tui/tests/tui.spec.ts

packages/ui/acp/tests/turns.spec.ts

@@ -49,6 +49,15 @@ describe('acp bridge — turn outcomes', () => {
       .rejects.toThrow(/turn failed: provider boom/)
   })
 
+  it('rejects an ordinary plugin turn failure through the same ACP boundary', async () => {
+    harness = await makeBridgeHarness({ storageDir, script: [textResponse('must not run')] })
+    harness.ctx.on('agent/pre-step', () => { throw new Error('plugin pre-step failed') })
+    const sessionId = await newSession(harness)
+
+    await expect(harness.client.prompt({ sessionId, prompt: [{ type: 'text', text: 'go' }] }))
+      .rejects.toThrow(/turn failed: plugin pre-step failed/)
+  })
+
   it('streams a tool call as tool_call then tool_call_update', async () => {
     harness = await makeBridgeHarness({
       storageDir,