feat: render sync server messages as rich text

[timarnoldev]

Summary

• Pass type="rich" to showText() when displaying the sync server message, enabling HTML rendering via QTextBrowser.setHtml()
• Plain-text messages continue to render identically — setHtml() handles plain strings the same as setPlainText()
• Allows self-hosted sync servers to send formatted post-sync messages (e.g. styled statistics, notices with links, tables)

Context

The /sync/meta response includes a msg field that is displayed to the user after sync. The display widget is already a QTextBrowser (which supports Qt rich text/HTML), but showText() is called with the default type="text", routing through setPlainText().

The showText helper already has full HTML support — it just needs type="rich":

# qt/aqt/utils.py
text = QTextBrowser()
text.setOpenExternalLinks(True)
if type == "text":
    text.setPlainText(txt)    # current path
else:
    text.setHtml(txt)         # proposed path

Security: QTextBrowser does not execute JavaScript — only static HTML/CSS. The sync server is explicitly configured and trusted by the user.

[abdnh]

We'll need to confirm if this won't cause issues with messages returned by AnkiWeb.

[timarnoldev]

@abdnh Are there public tests available? Since AnkiWeb is proprietary I can't review every possible case. Is there a list of messages coming from AnkiWeb available?

[abdnh]

It's not publicly available. We're still in the process of transitioning management and private access to AnkiHub. I'll check and get back to this.