nisse-review: read long files in parts; a retry starts afresh

From its failed review of #156: read_file stopped at 20,000 characters
with no way on, so the reviewer hunted each file's end a definition at a
time and ran out of turns; its retry carried every read before it, and a
model call timed out. Both drafts were lost.

- read_file takes a start line and says where the next part starts.
- Each run's view starts at its brief (Transcript.since); the log keeps
  the rest.
- A run out of turns with points drafted posts them as a partial review.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

nisse-core/tests/test_state.py

@@ -121,3 +121,17 @@ def test_newer_schema_is_refused(db: Path) -> None:
         pass
     with pytest.raises(StateSchemaError, match="newer"):
         StateStore(db, schema_version=1)
+
+
+def test_a_transcript_since_an_event_views_only_what_follows(tmp_path: Path) -> None:
+    from nisse_core.log.canonical import Fact
+
+    with StateStore(tmp_path / "s.db") as store:
+        store.open_work_item("w", title="t", scope="r", position="p", cause="t")
+        whole = store.transcript("w", "orchestrator")
+        first = whole.append(Fact(text="the failed attempt"))
+        whole.append(Fact(text="the retry's brief"))
+        fresh = whole.since(first)
+        assert [e.event.text for e in fresh.view()] == ["the retry's brief"]
+        assert len(fresh.read()) == 2  # the log keeps everything
+        assert len(whole.view()) == 2