🎉 Initial commit

src/opcda_diagnozer/report/jsonl.py

@@ -0,0 +1,25 @@
+"""Rotating JSONL reporter — the primary evidence trail (IMPLEMENTATION_PLAN §5.1).
+
+Phase 2 adds: size-based rotation with ``backups`` kept, atomic-ish append,
+and a header line carrying the config digest for provenance.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from opcda_diagnozer.events import DiagEvent
+
+
+class JsonlReporter:
+    """One JSON event per line, rotated by size — implemented in Phase 2."""
+
+    def __init__(self, directory: str | Path, max_mb: int = 50, backups: int = 10) -> None:
+        self._directory = Path(directory)
+        self._max_mb = max_mb
+        self._backups = backups
+
+    def emit(self, event: DiagEvent) -> None:
+        raise NotImplementedError(
+            "Phase 2: JSONL reporter (docs/IMPLEMENTATION_PLAN.md §5.1)"
+        )