Improve MarkdownLabel sizing and bubble layout

* Refine ChatMessage::resizeEvent to clamp the minimum width to 90 % of
the widget width while preserving any pre‑existing minimum.
* Add 4 px padding to the bubble backgrounds so text no longer touches
the edges.
* Adjust MarkdownLabel::heightForWidth to include an additional 8 px of
vertical padding.
* Implement sizeHint() in MarkdownLabel to honor the widget’s minimum
width when queried by layouts.
* Increase the horizontal padding used when computing the longest line
width from 10 px to 20 px for a more comfortable visual appearance.

These tweaks fix layout glitches that appeared when resizing the chat
window and improve the overall readability of Markdown content.

Author: cristianadam

llamachatmessage.cpp

@@ -227,7 +227,9 @@ void ChatMessage::buildUI()
 
 void ChatMessage::resizeEvent(QResizeEvent *ev)
 {
-    m_markdownLabel->setMinimumWidth(qMin(m_markdownLabel->minimumWidth(), int(width() * 0.9)));
+    const int minWidth = qMin(m_markdownLabel->minimumWidth(),
+                              qMax(m_markdownLabel->minimumWidth(), int(width() * 0.9)));
+    m_markdownLabel->setMinimumWidth(m_msg.role == "user" ? minWidth : int(width() * 0.9));
 }
 
 bool ChatMessage::eventFilter(QObject *obj, QEvent *event)
@@ -300,6 +302,7 @@ void ChatMessage::applyStyleSheet()
         QTextBrowser#BubbleUser {
             background: Token_Background_Muted;
             border-radius: 8px;
+            padding: 4px 4px;
         }
         QTextBrowser#BubbleAssistant {
             background: Token_Background_Default;

llamamarkdownwidget.cpp

@@ -270,20 +270,27 @@ int MarkdownLabel::heightForWidth(int w) const
     // (this does not change the widget’s real geometry)
     QTextDocument *doc = const_cast<QTextDocument *>(document());
     doc->setTextWidth(w);
-    return qRound(doc->size().height());
+    return qRound(doc->size().height() + 8);
 }
 
 void MarkdownLabel::invalidate()
 {
     m_markdownConversionTimer.invalidate();
 }
 
+QSize MarkdownLabel::sizeHint() const
+{
+    QSize sh = QTextBrowser::sizeHint();
+    sh.setWidth(minimumWidth());
+    return sh;
+}
+
 void MarkdownLabel::adjustMinimumWidth(const QString &markdown)
 {
     const QStringList lines = markdown.split('\n');
     const QString longestLine = *std::ranges::max_element(lines, std::less{}, &QString::length);
     QFontMetrics fm(font());
-    const int longestLineWidth = fm.horizontalAdvance(longestLine) + 10;
+    const int longestLineWidth = fm.horizontalAdvance(longestLine) + 20;
 
     if (minimumWidth() == 0 || (lines.size() < 5 && minimumWidth() < longestLineWidth))
         setMinimumWidth(longestLineWidth);

llamamarkdownwidget.h

@@ -21,6 +21,7 @@ class MarkdownLabel : public QTextBrowser
     void resizeEvent(QResizeEvent *event) override;
     int heightForWidth(int w) const override;
     void invalidate();
+    QSize sizeHint() const override;
 
 signals:
     void copyToClipboard(const QString &verbatimText, const QString &highlightedText);