feat(layout-review): address review findings on pages 4-6

Find Unusual Values (06_outlier_detector) — coming-soon stub:
- Anchor the disabled Method on IQR (multiplier 1.5), not Z-score, per
  the logged robustness decision.
- Drop the redundant feature bullet list (kept alert + greyed controls
  + disabled button); also fixes the MAD-only-in-bullets mismatch.
- Remove the live uploader that dead-ended into disabled controls.

Clean Text (02_text_cleaner):
- Add an inline hidden-character legend (3 swatches reusing the actual
  badge classes) beside the canonical "Show hidden characters" toggle.
- Unify the two hidden-char toggles: preview one is canonical; the
  Results bare checkbox is wrapped in a field + bound note.
- Describe all three presets (minimal / excel-hygiene / paranoid).
- Give "Changes by column" a real "column" header instead of the
  grey index-gutter style.

Standardize Formats (03_format_standardizer):
- Make preset-vs-control precedence legible: preset shows Custom with a
  "modified" marker + base tag, diverging controls flag the winning
  value (same pattern as Fix Missing Values).
- Replace the dead-end unparseable alert with a real "Unparseable
  cells (47)" expander the alert now points to.
- Honest preview caption: "5 of 6 columns (notes skipped)".
Intake pattern (the cross-page reference) left untouched.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

layout-review/02_text_cleaner.html

@@ -54,7 +54,12 @@
         <summary>Preview: contacts_messy.csv</summary>
         <div class="dt-expander-body">
           <p class="dt-caption">4,120 rows, 4 columns</p>
-          <div class="dt-check on" style="margin-top:2px"><span class="box"><span class="dt-mi">check</span></span> Show hidden characters in preview</div>
+          <div class="dt-check on" style="margin-top:2px"><span class="box"><span class="dt-mi">check</span></span> Show hidden characters</div>
+          <div style="display:flex;flex-wrap:wrap;align-items:center;gap:14px;margin-top:6px;font-size:12px;color:var(--ink-secondary)">
+            <span style="display:inline-flex;align-items:center;gap:6px"><span class="hidden-char hidden-whitespace" style="cursor:default">·</span> Whitespace</span>
+            <span style="display:inline-flex;align-items:center;gap:6px"><span class="hidden-char hidden-special" style="cursor:default">”</span> Smart / special</span>
+            <span style="display:inline-flex;align-items:center;gap:6px"><span class="hidden-char hidden-control" style="cursor:default">␣</span> Control</span>
+          </div>
           <div class="dt-table-wrap" style="margin-top:8px">
             <table class="dt-table">
               <thead><tr><th class="idx"></th><th>name</th><th>email</th><th>company</th><th>notes</th></tr></thead>
@@ -82,7 +87,11 @@
               <span class="dt-radio"><span class="dot"></span> minimal</span>
               <span class="dt-radio"><span class="dot"></span> paranoid</span>
             </div>
-            <div class="dt-help-text">excel-hygiene: trim, collapse whitespace, fold smart quotes, strip invisible chars, normalize line endings, NFC.</div>
+            <div class="dt-help-text">
+              minimal: trim and collapse whitespace only — no character substitutions.<br>
+              excel-hygiene: trim, collapse whitespace, fold smart quotes, strip invisible chars, normalize line endings, NFC.<br>
+              paranoid: everything in excel-hygiene plus strip control characters, strip BOM, and NFKC compatibility fold (lossy).
+            </div>
           </div>
 
           <details class="dt-expander">
@@ -143,17 +152,20 @@
         <div class="dt-metric"><div class="label">Columns processed</div><div class="value">4</div></div>
       </div>
 
-      <div class="dt-check on"><span class="box"><span class="dt-mi">check</span></span> Show hidden characters (NBSP, ZWSP, smart quotes, control chars…)</div>
+      <div class="dt-field">
+        <div class="dt-check on"><span class="box"><span class="dt-mi">check</span></span> Show hidden characters (NBSP, ZWSP, smart quotes, control chars…)</div>
+        <div class="dt-help-text">Same setting as “Show hidden characters” in the preview above — toggling either updates both.</div>
+      </div>
 
       <h4>Changes by column</h4>
       <div class="dt-table-wrap" style="max-width:360px">
         <table class="dt-table">
-          <thead><tr><th class="idx"></th><th>cells_changed</th></tr></thead>
+          <thead><tr><th>column</th><th>cells_changed</th></tr></thead>
           <tbody>
-            <tr><td class="idx">company</td><td>1,604</td></tr>
-            <tr><td class="idx">name</td><td>1,210</td></tr>
-            <tr><td class="idx">notes</td><td>982</td></tr>
-            <tr><td class="idx">email</td><td>151</td></tr>
+            <tr><td>company</td><td>1,604</td></tr>
+            <tr><td>name</td><td>1,210</td></tr>
+            <tr><td>notes</td><td>982</td></tr>
+            <tr><td>email</td><td>151</td></tr>
           </tbody>
         </table>
       </div>