fix: frame JSONL index reads on LF, not str.splitlines()

Four readers of the per-Goal run index frame it with `str.splitlines()`
(`history.py::repair_index_duplicates`, `run_index_rebuild.py::read_index_rows`,
`pending_intent.py::_actual_work_window`,
`monitor_poll.py::_find_monitor_poll_turn`). The index is written with
`json.dumps(..., ensure_ascii=False)`, which keeps U+0085, U+2028 and U+2029
inside a value verbatim — and `str.splitlines()` treats all three as line
breaks. A record holding one in a text field arrives as two fragments, both
fail `json.loads`, and the row is silently dropped.

Frame on LF instead. A trailing `\r` from a CRLF file stays harmless because
JSON treats it as whitespace.

Reproduced before the change: one record containing U+0085 yields zero parsed
rows; after it yields the record intact. The new test fails on
`read_index_rows` when only that function is reverted to `splitlines()` and
passes with the fix.

Validation: `pytest -q tests/control_plane/test_run_index_jsonl_framing.py` ->
2 passed; `ruff check` on the five files reports `All checks passed!`.

Signed-off-by: kokokoXUY <13682395396@163.com>

Rebased onto current main.

Rebased onto current main.

Rebased edit-on-current-main: the previous head copied whole files from an older
base and reverted upstream changes in them; this head applies only our edit to
current main.

Author: kokokoXUY

loopx/capabilities/periodic_report/pending_intent.py

@@ -760,7 +760,7 @@ def _actual_work_window(
     run_index = runtime_root / "goals" / goal_id / "runs" / "index.jsonl"
     if run_index.is_file():
         try:
-            rows = run_index.read_text(encoding="utf-8").splitlines()
+            rows = run_index.read_text(encoding="utf-8").split("\n")
         except OSError:
             rows = []
         for raw_row in rows:

loopx/control_plane/quota/monitor_poll.py

@@ -387,7 +387,7 @@ def _find_monitor_poll_turn(
     normalized_todo_id = normalize_todo_id(todo_id) if todo_id else None
     normalized_target_key = str(target_key or "").strip() or None
     try:
-        lines = index_path.read_text(encoding="utf-8").splitlines()
+        lines = index_path.read_text(encoding="utf-8").split("\n")
     except OSError:
         return None
     for line in reversed(lines):

loopx/control_plane/runtime/run_index_rebuild.py

@@ -38,7 +38,7 @@ def _event_identity(record: dict[str, Any]) -> dict[str, Any]:
 
 
 def read_index_rows(index_path: Path) -> tuple[list[str], list[tuple[int, dict[str, Any]]]]:
-    raw_lines = index_path.read_text(encoding="utf-8").splitlines()
+    raw_lines = index_path.read_text(encoding="utf-8").split("\n")
     rows: list[tuple[int, dict[str, Any]]] = []
     for line_number, line in enumerate(raw_lines, start=1):
         if not line.strip():

loopx/history.py

@@ -725,7 +725,7 @@ def repair_index_duplicates(
             else nullcontext()
         )
         with lock:
-            raw_lines = index_path.read_text(encoding="utf-8").splitlines()
+            raw_lines = index_path.read_text(encoding="utf-8").split("\n")
             grouped: dict[tuple[str, str, str], list[tuple[int, dict[str, Any]]]] = {}
             for line_number, line in enumerate(raw_lines, start=1):
                 if not line.strip():

tests/control_plane/test_run_index_jsonl_framing.py

@@ -0,0 +1,40 @@
+"""Record framing for the JSONL run index."""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+from loopx.control_plane.runtime.run_index_rebuild import read_index_rows
+
+NEL = "\x85"
+
+
+def test_run_index_record_with_a_raw_separator_stays_one_record(tmp_path: Path) -> None:
+    """`json.dumps(..., ensure_ascii=False)` keeps U+0085 verbatim in a value.
+
+    `str.splitlines()` treats U+0085, U+2028 and U+2029 as line breaks, so the
+    record arrived as two fragments that both failed to parse and the row was
+    dropped instead of being read.
+    """
+
+    index = tmp_path / "run_index.jsonl"
+    record = {"agent_id": "agent-a", "text": f"note{NEL}with-nel"}
+    index.write_text(json.dumps(record, ensure_ascii=False) + "\n", encoding="utf-8")
+
+    _, rows = read_index_rows(index)
+
+    assert [row for _, row in rows] == [record]
+
+
+def test_run_index_ordinary_records_are_unaffected(tmp_path: Path) -> None:
+    index = tmp_path / "run_index.jsonl"
+    records = [{"agent_id": "agent-a", "index": value} for value in range(3)]
+    index.write_text(
+        "".join(json.dumps(row, ensure_ascii=False) + "\n" for row in records),
+        encoding="utf-8",
+    )
+
+    _, rows = read_index_rows(index)
+
+    assert [row for _, row in rows] == records