feat(adapter): implement Balabit CSV parser

tests/test_balabit_adapter.py

@@ -34,3 +34,62 @@ def test_segment_dataclass():
     assert s.events == events
     assert s.click_x == 100
     assert s.session_id == "user1_s1"
+
+
+def _write_csv(path: Path, rows: list[str]) -> None:
+    """Helper to write a Balabit-format CSV with header."""
+    header = "record timestamp,client timestamp,button,state,x,y"
+    path.write_text(header + "\n" + "\n".join(rows) + "\n", encoding="utf-8")
+
+
+class TestParseSessionCsv:
+    def test_parses_basic_rows(self, tmp_path):
+        from ai_mouse.data_adapters.balabit import parse_session_csv
+        csv = tmp_path / "session_1"
+        _write_csv(csv, [
+            "1500000000.000,0.000,NoButton,Move,100,200",
+            "1500000000.050,0.050,NoButton,Move,110,210",
+            "1500000000.100,0.100,Left,Pressed,120,220",
+        ])
+        events = parse_session_csv(csv)
+        assert len(events) == 3
+        assert events[0].t_ms == 0
+        assert events[0].state == "Move"
+        assert events[0].x == 100
+        assert events[2].t_ms == 100
+        assert events[2].state == "Pressed"
+        assert events[2].button == "Left"
+
+    def test_handles_float_timestamps(self, tmp_path):
+        """Client timestamps are floats in seconds; we convert to int ms."""
+        from ai_mouse.data_adapters.balabit import parse_session_csv
+        csv = tmp_path / "session_2"
+        _write_csv(csv, [
+            "0,1.234,NoButton,Move,50,60",
+            "0,1.250,NoButton,Move,55,65",
+        ])
+        events = parse_session_csv(csv)
+        assert events[0].t_ms == 1234
+        assert events[1].t_ms == 1250
+
+    def test_skips_malformed_rows(self, tmp_path):
+        """Rows with bad data are logged and skipped, not raised."""
+        from ai_mouse.data_adapters.balabit import parse_session_csv
+        csv = tmp_path / "session_3"
+        _write_csv(csv, [
+            "0,0.000,NoButton,Move,100,200",
+            "BROKEN_ROW",
+            "0,abc,NoButton,Move,100,200",   # bad timestamp
+            "0,0.100,NoButton,Move,150,250",
+        ])
+        events = parse_session_csv(csv)
+        assert len(events) == 2
+        assert events[0].x == 100
+        assert events[1].x == 150
+
+    def test_returns_empty_list_for_empty_file(self, tmp_path):
+        from ai_mouse.data_adapters.balabit import parse_session_csv
+        csv = tmp_path / "session_4"
+        csv.write_text("record timestamp,client timestamp,button,state,x,y\n", encoding="utf-8")
+        events = parse_session_csv(csv)
+        assert events == []