test: load overlap blob from fixture and tighten minimal bash asserts

Read the task_message overlap toolUseResult from real_session_all_tool_types
instead of duplicating an inline dict. Pin minimal fixture bash stdout, exit
code, and message index. Document JSONDecodeError skip path in malformed_lines.

Author: clean6378-max-it

scripts/gen_real_session_fixtures.py

@@ -243,6 +243,10 @@ def write_malformed_lines() -> None:
         for obj in valid:
             f.write(_line(obj))
         f.write("\n")
+        f.write(
+            "# parse_session skips lines where json.loads raises JSONDecodeError "
+            "(blank, garbage, truncated JSON below).\n"
+        )
         f.write("{not valid json\n")
         f.write('{"type": "user", "timestamp": "2026-05-26T10:02:00Z", "message": {"content": ')
         f.write("\n")

tests/fixtures/real_session_malformed_lines.jsonl

@@ -1,6 +1,7 @@
 {"type": "user", "timestamp": "2026-05-26T10:00:00Z", "cwd": "/sanitized/project/path", "message": {"content": [{"type": "text", "text": "Valid line before malformed section"}]}, "sessionId": "session-sanitized-malformed-lines"}
 {"type": "assistant", "timestamp": "2026-05-26T10:01:00Z", "message": {"model": "claude-sanitized", "content": [{"type": "text", "text": "Recovered after bad lines."}], "usage": {"input_tokens": 10, "output_tokens": 5}}, "sessionId": "session-sanitized-malformed-lines"}
 
+# parse_session skips lines where json.loads raises JSONDecodeError (blank, garbage, truncated JSON below).
 {not valid json
 {"type": "user", "timestamp": "2026-05-26T10:02:00Z", "message": {"content": 
 {"type": "user", "timestamp": "2026-05-26T10:03:00Z", "cwd": "/sanitized/project/path", "message": {"content": [{"type": "text", "text": "Valid line after malformed section"}]}, "toolUseResult": {"stderr": "warn only", "exitCode": 1}, "sessionId": "session-sanitized-malformed-lines"}

tests/test_real_session_fixtures.py

@@ -25,6 +25,27 @@ def _fixture_path(name: str) -> str:
     return os.path.join(FIXTURES_DIR, name)
 
 
+def _overlap_tool_result_from_all_tool_types_fixture() -> dict:
+    """Last toolUseResult in real_session_all_tool_types (task_message overlap blob)."""
+    path = _fixture_path("real_session_all_tool_types.jsonl")
+    overlap: dict | None = None
+    with open(path, encoding="utf-8") as f:
+        for line in f:
+            line = line.strip()
+            if not line or line.startswith("#"):
+                continue
+            entry = json.loads(line)
+            tr = entry.get("toolUseResult")
+            if isinstance(tr, dict) and tr.get("agentId") == "agent-sanitized-overlap":
+                overlap = tr
+    if overlap is None:
+        pytest.fail(
+            "overlap toolUseResult (agent-sanitized-overlap) missing from "
+            "real_session_all_tool_types.jsonl"
+        )
+    return overlap
+
+
 def _assert_session_shape(session: dict) -> None:
     assert isinstance(session["session_id"], str) and session["session_id"]
     assert isinstance(session["title"], str) and session["title"] not in (
@@ -61,12 +82,12 @@ def test_real_fixture_parses_with_expected_message_count(
 
 def test_real_session_minimal_has_bash_tool_result() -> None:
     session = parse_session(_fixture_path("real_session_minimal.jsonl"))
-    parsed_types = [
-        m["tool_result_parsed"]["result_type"]
-        for m in session["messages"]
-        if m.get("tool_result_parsed")
-    ]
-    assert "bash" in parsed_types
+    assert len(session["messages"]) == _FIXTURE_MESSAGE_COUNTS["real_session_minimal.jsonl"]
+    parsed = session["messages"][2]["tool_result_parsed"]
+    assert parsed is not None
+    assert parsed["result_type"] == "bash"
+    assert parsed["stdout"] == "sanitized output\n"
+    assert parsed["exit_code"] == 0
 
 
 def test_real_session_all_tool_types_covers_dispatch_predicates() -> None:
@@ -152,12 +173,7 @@ def test_task_completed_with_message_key_matches_task_message_first() -> None:
 
 
 def test_overlap_blob_from_all_tool_types_fixture_locks_task_message_order() -> None:
-    tr = {
-        "agentId": "agent-sanitized-overlap",
-        "totalDurationMs": 500,
-        "status": "completed",
-        "message": "status update sanitized",
-    }
+    tr = _overlap_tool_result_from_all_tool_types_fixture()
     result = _parse_tool_result(tr)
     assert result is not None
     assert result["result_type"] == "task"