refactor: enhance summarization widget with streaming support and text accumulation

tests/test_summarization.py

@@ -1,6 +1,7 @@
 """Tests for the summarization event pipeline and display widgets."""
 
 from EvoScientist.stream.emitter import StreamEventEmitter
+from EvoScientist.stream.events import _extract_summarization_text
 from EvoScientist.stream.state import StreamState
 
 
@@ -44,12 +45,12 @@ class TestSummarizationState:
         assert etype == "summarization"
         assert state.summarization_text == "summary"
 
-    def test_overwrites_previous(self):
-        """Each summarization replaces (not appends) the previous text."""
+    def test_accumulates_chunks(self):
+        """Summarization chunks are accumulated (streaming)."""
         state = StreamState()
         state.handle_event({"type": "summarization", "content": "first"})
         state.handle_event({"type": "summarization", "content": "second"})
-        assert state.summarization_text == "second"
+        assert state.summarization_text == "firstsecond"
 
     def test_get_display_args_includes_field(self):
         state = StreamState()
@@ -158,6 +159,24 @@ class TestSummarizationWidget:
         w._content = "x" * 2500
         assert w._char_count_label() == "2.5k chars"
 
+    def test_append_text(self):
+        from EvoScientist.cli.widgets.summarization_widget import SummarizationWidget
+
+        w = SummarizationWidget()
+        w.append_text("hello ")
+        w.append_text("world")
+        assert w._content == "hello world"
+        assert w._is_active is True
+
+    def test_finalize(self):
+        from EvoScientist.cli.widgets.summarization_widget import SummarizationWidget
+
+        w = SummarizationWidget()
+        w.append_text("some summary")
+        w.finalize()
+        assert w._is_active is False
+        assert w._collapsed is True
+
     def test_toggle_collapsed(self):
         from EvoScientist.cli.widgets.summarization_widget import SummarizationWidget
 
@@ -167,3 +186,48 @@ class TestSummarizationWidget:
         assert w._collapsed is False
         w._collapsed = not w._collapsed
         assert w._collapsed is True
+
+
+# ---------------------------------------------------------------------------
+# _extract_summarization_text helper
+# ---------------------------------------------------------------------------
+
+
+class TestExtractSummarizationText:
+    """Content extraction from summarization chunks."""
+
+    def test_string_content(self):
+        class Msg:
+            content = "hello world"
+        assert _extract_summarization_text(Msg()) == "hello world"
+
+    def test_content_blocks(self):
+        class Msg:
+            content = [{"type": "text", "text": "part1"}, {"type": "text", "text": "part2"}]
+        assert _extract_summarization_text(Msg()) == "part1part2"
+
+    def test_content_blocks_with_index(self):
+        """Content blocks may include 'index' field — should still extract text."""
+        class Msg:
+            content = [{"type": "text", "text": " vs", "index": 1}]
+        assert _extract_summarization_text(Msg()) == " vs"
+
+    def test_empty_list(self):
+        class Msg:
+            content = []
+        assert _extract_summarization_text(Msg()) == ""
+
+    def test_no_content_attr(self):
+        class Msg:
+            pass
+        assert _extract_summarization_text(Msg()) == ""
+
+    def test_mixed_block_types(self):
+        class Msg:
+            content = [{"type": "text", "text": "hello"}, {"type": "image", "url": "..."}]
+        assert _extract_summarization_text(Msg()) == "hello"
+
+    def test_string_blocks_in_list(self):
+        class Msg:
+            content = ["hello", "world"]
+        assert _extract_summarization_text(Msg()) == "helloworld"