fix(tui): don't double-render finish_scan section headings

strix/interface/tui/renderers/finish_renderer.py

@@ -1,3 +1,4 @@
+import re
 from typing import Any, ClassVar
 
 from rich.text import Text
@@ -10,6 +11,23 @@
 FIELD_STYLE = "bold #4ade80"
 
 
+def _strip_leading_heading(value: str, section: str) -> str:
+    """Drop a leading markdown heading that just repeats the section label.
+
+    The finish_scan tool prompts the model to write markdown in every field, and
+    the models routinely open each with a ``# <Section>`` heading (e.g.
+    ``# Executive Summary``). This renderer also prints its own styled section
+    label above the value, so that heading renders twice. Strip a leading
+    ``#``-heading whose text matches this section (case-insensitively) so the
+    label isn't duplicated; leave all other content — including headings that
+    say something else — untouched.
+    """
+    stripped = value.lstrip()
+    pattern = rf"^#{{1,6}}\s+{re.escape(section)}\s*\n+"
+    m = re.match(pattern, stripped, flags=re.IGNORECASE)
+    return stripped[m.end() :] if m else value
+
+
 @register_tool_renderer
 class FinishScanRenderer(BaseToolRenderer):
     tool_name: ClassVar[str] = "finish_scan"
@@ -32,25 +50,25 @@ def render(cls, tool_data: dict[str, Any]) -> Static:
             text.append("\n\n")
             text.append("Executive Summary", style=FIELD_STYLE)
             text.append("\n")
-            text.append(executive_summary)
+            text.append(_strip_leading_heading(executive_summary, "Executive Summary"))
 
         if methodology:
             text.append("\n\n")
             text.append("Methodology", style=FIELD_STYLE)
             text.append("\n")
-            text.append(methodology)
+            text.append(_strip_leading_heading(methodology, "Methodology"))
 
         if technical_analysis:
             text.append("\n\n")
             text.append("Technical Analysis", style=FIELD_STYLE)
             text.append("\n")
-            text.append(technical_analysis)
+            text.append(_strip_leading_heading(technical_analysis, "Technical Analysis"))
 
         if recommendations:
             text.append("\n\n")
             text.append("Recommendations", style=FIELD_STYLE)
             text.append("\n")
-            text.append(recommendations)
+            text.append(_strip_leading_heading(recommendations, "Recommendations"))
 
         if not (executive_summary or methodology or technical_analysis or recommendations):
             text.append("\n  ")

tests/test_finish_renderer.py

@@ -0,0 +1,65 @@
+"""Tests for the finish_scan TUI renderer (section-heading de-duplication)."""
+
+from __future__ import annotations
+
+from rich.text import Text
+
+from strix.interface.tui.renderers.finish_renderer import (
+    FinishScanRenderer,
+    _strip_leading_heading,
+)
+
+
+def _plain(static: object) -> str:
+    content = static.content  # type: ignore[attr-defined]
+    return content.plain if isinstance(content, Text) else str(content)
+
+
+def _render(**args: str) -> str:
+    return _plain(FinishScanRenderer.render({"status": "completed", "args": args}))
+
+
+# --- _strip_leading_heading -------------------------------------------------
+
+
+def test_strips_matching_leading_heading() -> None:
+    assert _strip_leading_heading("# Executive Summary\n\nBody", "Executive Summary") == "Body"
+    assert _strip_leading_heading("## Methodology\nSteps", "Methodology") == "Steps"
+
+
+def test_strip_is_case_and_whitespace_insensitive() -> None:
+    assert _strip_leading_heading("#  technical analysis \n\nX", "Technical Analysis") == "X"
+
+
+def test_keeps_a_different_leading_heading() -> None:
+    # A heading that isn't the section label is real content — leave it.
+    val = "# Findings Overview\nY"
+    assert _strip_leading_heading(val, "Executive Summary") == val
+
+
+def test_keeps_body_when_no_heading() -> None:
+    assert _strip_leading_heading("No heading here", "Methodology") == "No heading here"
+
+
+def test_keeps_lone_heading_with_no_body() -> None:
+    # No trailing newline => not a section split; don't strip to empty.
+    assert _strip_leading_heading("# Recommendations", "Recommendations") == "# Recommendations"
+
+
+# --- end-to-end render ------------------------------------------------------
+
+
+def test_section_heading_rendered_once_not_twice() -> None:
+    # The model is prompted to write markdown and routinely opens each field
+    # with a `# <Section>` heading; the renderer also prints a styled label.
+    # Regression: both showed, doubling the heading. Now the field's leading
+    # heading is stripped so "Executive Summary" appears exactly once.
+    out = _render(executive_summary="# Executive Summary\n\nThe app is sound.")
+    assert out.count("Executive Summary") == 1
+    assert "The app is sound." in out
+
+
+def test_render_preserves_body_without_heading() -> None:
+    out = _render(methodology="White-box review of the diff.")
+    assert "Methodology" in out
+    assert "White-box review of the diff." in out