contact messages: mailto recipient is Brand <email>

The contact-email frame now carries the RFC-encoded recipient (John
Smith <john@example.com> → John%20Smith%20%3Cjohn@example.com%3E),
encoded server-side where the current brand lives; the link text stays
the bare address and the localized subject rides the query as before.

frontend/src/ContactOverlay.vue

@@ -20,10 +20,11 @@ const emit = defineEmits(['send', 'close'])
 const admin = computed(() => props.state.mode === 'admin')
 
 // The visitor dialog's title is the localized site contact label (the
-// {contact:} buttons' default label); the mailto link carries the
-// localized subject.
+// {contact:} buttons' default label). The mailto href carries the
+// server-encoded "Brand <email>" recipient and the localized subject;
+// the link text is the bare address.
 const mailto = computed(
-  () => `mailto:${props.state.email}?subject=${encodeURIComponent(props.state.subject)}`
+  () => `mailto:${props.state.mailtoTo}?subject=${encodeURIComponent(props.state.subject)}`
 )
 
 // Escape closes, like the paskia dialogs whose backdrop we share.

frontend/src/contact-main.js

@@ -31,6 +31,7 @@ const state = reactive({
   // link with subject prefilled.
   label: 'Contact us',
   email: '',
+  mailtoTo: '', // RFC-encoded "Brand <email>" recipient for the mailto href
   subject: '',
 })
 
@@ -145,6 +146,7 @@ function onPow(msg) {
 
 function onEmail(msg) {
   state.email = msg.email || ''
+  state.mailtoTo = msg.to || '' // RFC-encoded "Brand <email>" recipient
 }
 
 // An upload hit the end of the PoW quota: re-register (the server pushes

pagerite/messages.py

@@ -265,7 +265,17 @@ async def visitor_proven(ws: WebSocket, raw: dict) -> bytes | None:
     _quota[key] = POW_QUOTA
     await ws.send_json({"type": "pow", "quota": POW_QUOTA})
     if data.contact_email:
-        await ws.send_json({"type": "contact-email", "email": data.contact_email})
+        # The mailto recipient is "Brand <email>" (RFC-encoded here; the
+        # link text is the bare address, the subject is the client's
+        # localized contact_subject).
+        recipient = (
+            quote(f"{data.brand} <{data.contact_email}>", safe="@")
+            if data.brand.strip()
+            else quote(data.contact_email, safe="@")
+        )
+        await ws.send_json(
+            {"type": "contact-email", "email": data.contact_email, "to": recipient}
+        )
     return key