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

# Conflicts:
#	docs/architecture.md
#	docs/cordis-catalog/events.md
#	docs/core-data-structures/core.md
#	docs/event-producer-consumer.md
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/src/agent.ts
#	packages/core/agent/README.md
#	packages/core/agent/src/types.ts
#	packages/ui/acp/src/index.ts
#	packages/ui/tui/src/index.ts
#	packages/ui/tui/tests/harness.ts

packages/core/agent/tests/agent.spec.ts

@@ -188,6 +188,7 @@ describe('agentEvents()', () => {
 describe('explicit cancellation helpers', () => {
   it('exposes the closed typed cancellation cause at the Agent seam', () => {
     expectTypeOf<Parameters<Agent['cancel']>[0]>().toEqualTypeOf<AgentCancelCause | undefined>()
+    expectTypeOf<Parameters<Events['agent/cancel-requested']>[1]>().toEqualTypeOf<AgentCancelCause>()
   })
 
   it('reads only supported reasons from an explicit signal', () => {