Merge latest master into codex/llm-error-recovery-rfc

# Conflicts:
#	docs/architecture.md
#	docs/config-catalog.md
#	docs/cordis-catalog/events.md
#	docs/event-producer-consumer.md
#	docs/module-graph.md
#	docs/persistence-catalog.md
#	packages/cordis/tool-cordis/src/api-catalog.ts
#	packages/core/agent-loop/src/loop.ts
#	packages/core/agent/src/types.ts
#	packages/examples/agent-spine-demo/README.md
#	packages/examples/stdio-demo/README.md
#	packages/examples/stdio-demo/src/index.ts
#	packages/llm/llm-deepseek/README.md
#	packages/llm/llm-deepseek/src/adapter.ts
#	packages/llm/llm-deepseek/tests/adapter.spec.ts
#	packages/llm/llm/README.md
#	packages/llm/llm/src/error.ts
#	packages/llm/llm/tests/service.spec.ts
#	packages/sandbox/sandbox-policy/tsconfig.json
#	packages/ui/stdio/README.md
#	packages/ui/stdio/src/index.ts
#	packages/ui/stdio/tests/stdio.spec.ts
#	packages/ui/tui/src/index.ts
#	pnpm-lock.yaml
#	website/zh-CN/api/harness/events.md
#	website/zh-CN/api/harness/llm.md

packages/core/agent-loop/tests/request-recovery.spec.ts

@@ -419,8 +419,9 @@ describe('agent post-step and request-error lifecycle', () => {
     expect(seen).toBe(original)
   })
 
-  it('passes structured facts beside the original Error and records them on exhaustion', async () => {
+  it('passes structured facts beside the original Error and records its cause chain on exhaustion', async () => {
     const original = new LlmError('provider busy', 'RATE_LIMIT', {
+      cause: new Error('upstream connection reset'),
       status: 429,
       providerRetryAfterMs: 2_000,
       requestId: ProviderRequestId('req-9'),
@@ -455,7 +456,19 @@ describe('agent post-step and request-error lifecycle', () => {
     expect(Object.isFrozen(seenHistory)).toBe(true)
     expect(agent.session.events.at(-1)).toMatchObject({
       type: 'turn/end',
-      data: { reason: { kind: 'error', step: 1, failure: seenFailure } },
+      data: {
+        reason: {
+          kind: 'error',
+          step: 1,
+          failure: {
+            message: 'provider busy: upstream connection reset',
+            code: 'RATE_LIMIT',
+            status: 429,
+            providerRetryAfterMs: 2_000,
+            requestId: ProviderRequestId('req-9'),
+          },
+        },
+      },
     })
   })