feat(tool-delegate): return partial results on per-delegate timeout (k64 prereq 1 of 2, CONSUMER half)

docs/lanes/bp0-delegate-timeout-partial-consumer/after-probe.txt

@@ -0,0 +1,102 @@
+PATCHED TREE (working copy on top of 5ebf1da)
+DATE: 2026-09-03T07:33:00Z
+CMD: PYTHONPATH=modules/tool-delegate uv run python docs/lanes/bp0-delegate-timeout-partial-consumer/probe_timeout_contract.py
+
+Agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout; elapsed 0.01s). Partial output was preserved and is returned under 'partial_response' -- it is UNFINISHED, not a result. Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.
+Resumed agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout; elapsed 0.01s). Partial output was preserved and is returned under 'partial_response' -- it is UNFINISHED, not a result. Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.
+Agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout; elapsed 0.01s). Partial output was preserved and is returned under 'partial_response' -- it is UNFINISHED, not a result. Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.
+--- A. spawn timeout: result.success ---
+false
+
+--- A. spawn timeout: result.output ---
+{
+  "agent": "test-agent",
+  "completed": false,
+  "guidance": "INCOMPLETE: this delegate did not finish. The text in 'partial_response' is unfinished work salvaged from the agent mid-flight -- it has NOT been checked, concluded, or self-reviewed by that agent. Do not report it as a completed result and do not treat its conclusions as final. Re-delegate a narrower task or complete the work yourself; see metadata.recovery_message before considering this session for resumption.",
+  "metadata": {
+    "elapsed_s": "<elapsed>",
+    "recovery_message": "Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.",
+    "resumable": false,
+    "resume_status": "pending_child_cleanup",
+    "timeout_seconds": 0.01
+  },
+  "partial_available": true,
+  "partial_chars_total": 22,
+  "partial_response": "straggler got this far",
+  "partial_segments": 7,
+  "partial_source": "capability",
+  "partial_truncated": false,
+  "session_id": "0000000000000000-c7ab32b24e5947fc_test-agent",
+  "status": "timeout"
+}
+
+--- A. spawn timeout: delegate:error payload (elapsed_s dropped) ---
+{
+  "agent": "test-agent",
+  "error": "Agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout; elapsed 0.01s). Partial output was preserved and is returned under 'partial_response' -- it is UNFINISHED, not a result. Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.",
+  "error_type": "delegate_timeout",
+  "parallel_group_id": "parallel-timeout",
+  "parent_session_id": "parent-session-123",
+  "partial_available": true,
+  "partial_chars": 22,
+  "resumable": false,
+  "resume_status": "pending_child_cleanup",
+  "status": "timeout",
+  "sub_session_id": "<generated>",
+  "timeout_seconds": 0.01,
+  "tool_call_id": "call-timeout"
+}
+
+A. CONTRACT: status==timeout | 'response' absent==True | 'partial_available' present==True
+
+--- B. resume timeout: result.output ---
+{
+  "agent": "test-agent",
+  "completed": false,
+  "guidance": "INCOMPLETE: this delegate did not finish. The text in 'partial_response' is unfinished work salvaged from the agent mid-flight -- it has NOT been checked, concluded, or self-reviewed by that agent. Do not report it as a completed result and do not treat its conclusions as final. Re-delegate a narrower task or complete the work yourself; see metadata.recovery_message before considering this session for resumption.",
+  "metadata": {
+    "elapsed_s": "<elapsed>",
+    "recovery_message": "Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.",
+    "resumable": false,
+    "resume_status": "pending_child_cleanup",
+    "timeout_seconds": 0.01
+  },
+  "partial_available": true,
+  "partial_chars_total": 22,
+  "partial_response": "straggler got this far",
+  "partial_segments": 7,
+  "partial_source": "capability",
+  "partial_truncated": false,
+  "session_id": "child-session-001_test-agent",
+  "status": "timeout"
+}
+
+B. CONTRACT: status==timeout | 'response' absent==True | 'partial_available' present==True
+
+--- C. G-D1 sibling survival ---
+gather returned; completed siblings surviving = 2 of 2; discarded-completed-sibling count = 0
+
+--- D. normal completion: result.success ---
+true
+
+--- D. normal completion: result.output ---
+{
+  "agent": "test-agent",
+  "contract": {
+    "artifacts": [],
+    "conformant": null,
+    "findings": [],
+    "not_covered": [],
+    "reason": null,
+    "summary": null
+  },
+  "metadata": {},
+  "response": "the whole answer",
+  "session_id": "sub-1",
+  "status": "success",
+  "turn_count": 3
+}
+
+D. normal completion: serialized output
+{"response": "the whole answer", "session_id": "sub-1", "agent": "test-agent", "turn_count": 3, "status": "success", "metadata": {}, "contract": {"conformant": null, "reason": null, "summary": null, "findings": [], "not_covered": [], "artifacts": []}}
+

docs/lanes/bp0-delegate-timeout-partial-consumer/byte-identity-normal-completion.txt

@@ -0,0 +1,13 @@
+BYTE-IDENTITY CHECK -- normal (non-timeout) delegate completion
+DATE: 2026-09-03T07:33:09Z
+
+Section D of the probe is a NORMAL completion. Compared verbatim between the
+parent commit 5ebf1da (fail-before-probe.txt) and the patched tree (after-probe.txt).
+It includes the exact serialized string the model receives.
+
+$ diff <(sed -n "/^--- D./,$p" fail-before-probe.txt) <(sed -n "/^--- D./,$p" after-probe.txt)
+(no output -- IDENTICAL)
+
+RESULT: byte-identical. sha256 of each section:
+18dfd629b68861f7c11e2182a6d730f5e26cef39d48b8d4a9396b63b587a0ab1  D-before.txt
+18dfd629b68861f7c11e2182a6d730f5e26cef39d48b8d4a9396b63b587a0ab1  D-after.txt

docs/lanes/bp0-delegate-timeout-partial-consumer/fail-before-probe.txt

@@ -0,0 +1,82 @@
+PARENT COMMIT: 5ebf1dab1fba33539e15499698f33cb3b9fc2b78  (fix(activator): install a bundle root's package only when a declared module lives there; fail by name)
+DATE: 2026-09-03T07:29:51Z
+CMD: PYTHONPATH=modules/tool-delegate uv run python docs/lanes/bp0-delegate-timeout-partial-consumer/probe_timeout_contract.py
+
+Agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout). Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.
+Resumed agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout). Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.
+Agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout). Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.
+--- A. spawn timeout: result.success ---
+false
+
+--- A. spawn timeout: result.output ---
+{
+  "agent": "test-agent",
+  "metadata": {
+    "recovery_message": "Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.",
+    "resumable": false,
+    "resume_status": "pending_child_cleanup",
+    "timeout_seconds": 0.01
+  },
+  "session_id": "0000000000000000-d13c50c4216142b9_test-agent",
+  "status": "timed_out"
+}
+
+--- A. spawn timeout: delegate:error payload (elapsed_s dropped) ---
+{
+  "agent": "test-agent",
+  "error": "Agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout). Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.",
+  "error_type": "delegate_timeout",
+  "parallel_group_id": "parallel-timeout",
+  "parent_session_id": "parent-session-123",
+  "resumable": false,
+  "resume_status": "pending_child_cleanup",
+  "status": "timed_out",
+  "sub_session_id": "<generated>",
+  "timeout_seconds": 0.01,
+  "tool_call_id": "call-timeout"
+}
+
+A. CONTRACT: status==timed_out | 'response' absent==True | 'partial_available' present==False
+
+--- B. resume timeout: result.output ---
+{
+  "agent": "test-agent",
+  "metadata": {
+    "recovery_message": "Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.",
+    "resumable": false,
+    "resume_status": "pending_child_cleanup",
+    "timeout_seconds": 0.01
+  },
+  "session_id": "child-session-001_test-agent",
+  "status": "timed_out"
+}
+
+B. CONTRACT: status==timed_out | 'response' absent==True | 'partial_available' present==False
+
+--- C. G-D1 sibling survival ---
+gather returned; completed siblings surviving = 2 of 2; discarded-completed-sibling count = 0
+
+--- D. normal completion: result.success ---
+true
+
+--- D. normal completion: result.output ---
+{
+  "agent": "test-agent",
+  "contract": {
+    "artifacts": [],
+    "conformant": null,
+    "findings": [],
+    "not_covered": [],
+    "reason": null,
+    "summary": null
+  },
+  "metadata": {},
+  "response": "the whole answer",
+  "session_id": "sub-1",
+  "status": "success",
+  "turn_count": 3
+}
+
+D. normal completion: serialized output
+{"response": "the whole answer", "session_id": "sub-1", "agent": "test-agent", "turn_count": 3, "status": "success", "metadata": {}, "contract": {"conformant": null, "reason": null, "summary": null, "findings": [], "not_covered": [], "artifacts": []}}
+

docs/lanes/bp0-delegate-timeout-partial-consumer/fail-before-tests.txt

@@ -0,0 +1,51 @@
+PARENT COMMIT: 5ebf1dab1fba33539e15499698f33cb3b9fc2b78
+CMD: uv run pytest <test_delegate_timeout_partial.py with a 2-line ImportError shim> -q
+WHY THE SHIM: on the parent commit the module exports no DEFAULT_PARTIAL_MAX_CHARS, so the real
+file dies at collection and yields ONE error instead of per-behaviour evidence. The shim defaults
+that one constant and changes nothing else, so each test fails on its own assertion.
+
+        """
+        tool = _make_tool()
+>       assert tool.partial_max_chars == DEFAULT_PARTIAL_MAX_CHARS == 20000
+               ^^^^^^^^^^^^^^^^^^^^^^
+E       AttributeError: 'DelegateTool' object has no attribute 'partial_max_chars'
+
+modules/tool-delegate/tests/test_zz_failbefore_shim.py:349: AttributeError
+____________ test_resume_timeout_carries_the_same_partial_contract _____________
+
+    @pytest.mark.asyncio
+    async def test_resume_timeout_carries_the_same_partial_contract():
+        """The resume path is a second timeout call site; it must not diverge."""
+        hooks = _hooks()
+        tool = _make_tool(
+            timeout=0.01,
+            resume_fn=AsyncMock(side_effect=_never_finishes),
+            partial_fn=lambda sid: {"text": "resumed partial", "segments": 3},
+        )
+        result = await _resume(tool, hooks)
+
+        assert result.success is False
+        assert "response" not in result.output
+>       assert result.output["status"] == "timeout"
+E       AssertionError: assert 'timed_out' == 'timeout'
+E         
+E         - timeout
+E         + timed_out
+E         ?     ++
+
+modules/tool-delegate/tests/test_zz_failbefore_shim.py:366: AssertionError
+------------------------------ Captured log call -------------------------------
+WARNING  amplifier_module_tool_delegate:__init__.py:2481 Resumed agent 'test-agent' timed out after 0.01s (delegate tool session-level timeout). Child cancellation cleanup is still in progress; do not resume this session until cleanup and persistence complete.
+=========================== short test summary info ============================
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_timeout_is_not_success_on_either_channel
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_partial_text_never_lands_on_the_success_key
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_straggler_returns_rather_than_raises_so_siblings_survive
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_no_partial_capability_degrades_to_no_partial_not_to_error
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_partial_capability_raising_does_not_break_the_timeout_path
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_async_partial_capability_is_supported
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_partial_text_is_capped_and_keeps_the_tail
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_malformed_partial_payload_is_ignored
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_timeout_event_carries_elapsed_and_partial_flags
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_partial_max_chars_default_is_shipped_not_swept
+FAILED modules/tool-delegate/tests/test_zz_failbefore_shim.py::test_resume_timeout_carries_the_same_partial_contract
+11 failed, 1 passed in 0.24s

docs/lanes/bp0-delegate-timeout-partial-consumer/patch-apply-check.txt

@@ -0,0 +1,13 @@
+APPLY.md's literal instruction, run against 5ebf1da:
+$ git apply --check PATCH-foundation-tool-delegate.diff
+error: patch failed: modules/tool-delegate/amplifier_module_tool_delegate/__init__.py:20
+error: modules/tool-delegate/amplifier_module_tool_delegate/__init__.py: patch does not apply
+exit=1
+
+$ git apply --3way --check PATCH-foundation-tool-delegate.diff
+error: repository lacks the necessary blob to perform 3-way merge.
+Falling back to direct application...
+error: patch failed: modules/tool-delegate/amplifier_module_tool_delegate/__init__.py:20
+error: modules/tool-delegate/amplifier_module_tool_delegate/__init__.py: patch does not apply
+Falling back to direct application...
+exit=1