fix(agent): avoid scratchpad false positives in markdown

tests/agent/test_trajectory.py

@@ -0,0 +1,36 @@
+from agent.trajectory import convert_scratchpad_to_think, has_incomplete_scratchpad
+
+
+def test_convert_scratchpad_to_think_rewrites_tags():
+    content = "<REASONING_SCRATCHPAD>think</REASONING_SCRATCHPAD> done"
+    assert convert_scratchpad_to_think(content) == "<think>think</think> done"
+
+
+def test_has_incomplete_scratchpad_detects_real_unclosed_tag():
+    content = "Answering...\n<REASONING_SCRATCHPAD>still thinking"
+    assert has_incomplete_scratchpad(content) is True
+
+
+def test_has_incomplete_scratchpad_ignores_fenced_code_block_mentions():
+    content = """Here is the grep output:
+
+```text
+<REASONING_SCRATCHPAD>
+```
+"""
+    assert has_incomplete_scratchpad(content) is False
+
+
+def test_has_incomplete_scratchpad_ignores_blockquote_mentions():
+    content = "> literal token <REASONING_SCRATCHPAD>\n\nFinal answer."
+    assert has_incomplete_scratchpad(content) is False
+
+
+def test_has_incomplete_scratchpad_ignores_inline_code_mentions():
+    content = "The user literally typed `<REASONING_SCRATCHPAD>` in the prompt."
+    assert has_incomplete_scratchpad(content) is False
+
+
+def test_has_incomplete_scratchpad_still_flags_real_tag_after_quote():
+    content = "> quoted literal <REASONING_SCRATCHPAD>\n\n<REASONING_SCRATCHPAD>real"
+    assert has_incomplete_scratchpad(content) is True