ui: drop remaining T212-only framing from dashboard + import lede

- portfolio.js empty-state CTA: "Import a T212 CSV" → "Import a portfolio CSV"
- settings.html lede: lead with broker-agnostic copy; relegate the T212
  export path to a smaller secondary line.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/static/js/portfolio.js

@@ -189,7 +189,7 @@
       '<div class="empty" style="padding:16px;">' +
         notice +
         'No portfolio loaded in this browser. ' +
-        '<a href="/settings#import">Import a T212 CSV →</a>' +
+        '<a href="/settings#import">Import a portfolio CSV →</a>' +
       '</div>';
   }
 

app/templates/settings.html

@@ -98,10 +98,12 @@
     <details class="settings-section" id="import" open>
       <summary class="settings-section__head">Import portfolio (CSV)</summary>
       <p class="settings-section__lede">
-        If you use Trading 212, export your pie as CSV
-        (<span class="neu">Investing &rarr; Your Pie &rarr; &middot;&middot;&middot; &rarr; Export</span>)
-        and drop the CSV here. We&rsquo;ll parse it and show a preview before
-        importing anywhere.
+        Drop a portfolio CSV from any broker &mdash; Trading 212 is recognised
+        natively and other formats (IBKR, Fidelity, Schwab&hellip;) are
+        auto-detected. We&rsquo;ll parse it and show a preview before importing
+        anywhere.
+        <br><span class="muted">T212 export path:
+        <span class="neu">Investing &rarr; Your Pie &rarr; &middot;&middot;&middot; &rarr; Export</span>.</span>
       </p>
 
       <div id="drop-zone" class="dz">