feat(text-cleaner): collapse options + auto-scroll to Results on run

After clicking Clean Text the user was left at the bottom of the
script with the Options block still expanded and no viewport movement
— they had to scroll to find the Results.

- Wrap the whole Options block in an outer ``st.expander("Options",
  expanded=not _has_result)``. After the Clean Text rerun, both
  Preview AND Options collapse, leaving the primary action button +
  Results as the only prominent elements above the fold. The inner
  Advanced-options expander is preserved as a nested expander
  (supported in Streamlit 1.36+; this repo pins 1.35+).
- Add a 1px anchor div ``#textclean-results-anchor`` immediately
  before the Results subheader.
- On Clean Text click, set a one-shot ``_textclean_scroll_to_results``
  flag in session state; on the next render, pop the flag and inject
  a tiny ``st.components.v1.html`` iframe whose ``<script>`` calls
  ``scrollIntoView`` on the parent document's anchor. One-shot so
  re-renders triggered by other widgets (Show-hidden toggle, etc.)
  don't jerk the viewport back to the top of Results.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/gui/pages/2_Text_Cleaner.py

@@ -123,9 +123,13 @@ st.divider()
 # ---------------------------------------------------------------------------
 # Options
 # ---------------------------------------------------------------------------
+#
+# Wrapped in an outer expander whose default state mirrors the preview
+# expander above: open before a result exists, folded once the user has
+# clicked Clean Text. Together they push the Results section to the top
+# of the visible area after a run.
 
-st.subheader("Options")
-
+with st.expander("Options", expanded=not _has_result):
     preset_label = st.radio(
         "Preset",
         ["excel-hygiene (recommended)", "minimal", "paranoid"],
@@ -215,10 +219,13 @@ if st.button("Clean Text", type="primary", use_container_width=True):
             st.stop()
     st.session_state["textclean_result"] = result
     st.session_state["textclean_input_name"] = uploaded.name
-    # Force a second rerun so the preview-section expander above sees
-    # the new result on its NEXT script pass and collapses itself.
-    # Without this the preview stays expanded until the user touches
-    # any other widget.
+    # One-shot flag picked up on the next pass to scroll the parent
+    # document to the Results anchor (see scroll snippet below).
+    st.session_state["_textclean_scroll_to_results"] = True
+    # Force a second rerun so the preview and options expanders see
+    # the new result on the NEXT script pass and collapse themselves.
+    # Without this they stay expanded until the user touches any
+    # other widget.
     st.rerun()
 
 result = st.session_state.get("textclean_result")
@@ -229,6 +236,16 @@ if result is None:
 # Results
 # ---------------------------------------------------------------------------
 
+# Anchor target for the auto-scroll snippet at the end of this block.
+# A bare ``<div id="...">`` survives Streamlit's HTML sanitizer (only
+# ``<script>`` is stripped), and a 1px-tall div doesn't visually shift
+# anything. Placed before the subheader so the scrolled-to viewport
+# starts a few pixels above the section heading rather than below it.
+st.markdown(
+    '<div id="textclean-results-anchor" style="height:1px"></div>',
+    unsafe_allow_html=True,
+)
+
 st.subheader("Results")
 
 pct = (result.cells_changed / result.cells_total * 100.0) if result.cells_total else 0.0
@@ -344,3 +361,30 @@ with dl_c:
 
 st.divider()
 st.caption("Runs locally. Your data never leaves this computer. | DataTools v3.0")
+
+# ---------------------------------------------------------------------------
+# Post-run auto-scroll
+# ---------------------------------------------------------------------------
+#
+# When the user clicks Clean Text, the preview + options collapse but
+# Streamlit by itself doesn't scroll — the Results section is at the
+# bottom of a tall script so the user has to find it. Inject a tiny
+# component-html iframe that calls ``scrollIntoView`` on the parent's
+# Results anchor. Streamlit's main page is same-origin with component
+# iframes so ``window.parent.document`` access is allowed.
+#
+# The flag is one-shot (``pop`` removes it) so re-renders triggered by
+# unrelated widgets in the Results section (e.g., the Show-hidden
+# toggle) don't yank the viewport back to the top of Results.
+if st.session_state.pop("_textclean_scroll_to_results", False):
+    from streamlit.components.v1 import html as _components_html
+    _components_html(
+        """
+        <script>
+          const doc = window.parent.document;
+          const target = doc.getElementById('textclean-results-anchor');
+          if (target) target.scrollIntoView({behavior: 'smooth', block: 'start'});
+        </script>
+        """,
+        height=0,
+    )