decode RFC 2047 subjects/sender names, parse RFC 2822 dates from IMAP envelopes

- decode RFC 2047 encoded words in subject and fromName via RFC2047Decoder
  before storing in MessageRecord (fixes =?utf-8?Q?...?= raw display)
- add RFC 2822 date formatters to Queries.parseDate (EEE, dd MMM yyyy HH:mm:ss Z)
  so IMAP envelope dates parse correctly instead of falling back to distantPast
- parseDate now tries ISO 8601, RFC 2822 with day-of-week, RFC 2822 without

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Packages/MagnumOpusCore/Sources/MailStore/Queries.swift

@@ -82,8 +82,29 @@ extension MailStore {
 		ISO8601DateFormatter()
 	}()
 
-	static func parseDate(_ iso: String) -> Date? {
-		isoFormatterWithFractional.date(from: iso) ?? isoFormatter.date(from: iso)
+	nonisolated(unsafe) private static let rfc2822Formatter: DateFormatter = {
+		let f = DateFormatter()
+		f.locale = Locale(identifier: "en_US_POSIX")
+		f.dateFormat = "EEE, dd MMM yyyy HH:mm:ss Z"
+		return f
+	}()
+
+	nonisolated(unsafe) private static let rfc2822FormatterNoDow: DateFormatter = {
+		let f = DateFormatter()
+		f.locale = Locale(identifier: "en_US_POSIX")
+		f.dateFormat = "dd MMM yyyy HH:mm:ss Z"
+		return f
+	}()
+
+	static func parseDate(_ dateString: String) -> Date? {
+		let trimmed = dateString.trimmingCharacters(in: .whitespaces)
+		// Try ISO 8601 first
+		if let d = isoFormatterWithFractional.date(from: trimmed) { return d }
+		if let d = isoFormatter.date(from: trimmed) { return d }
+		// Try RFC 2822 (IMAP envelope date format)
+		if let d = rfc2822Formatter.date(from: trimmed) { return d }
+		if let d = rfc2822FormatterNoDow.date(from: trimmed) { return d }
+		return nil
 	}
 
 	public static func toMessageSummary(_ record: MessageRecord) -> MessageSummary {

Packages/MagnumOpusCore/Sources/SyncEngine/SyncCoordinator.swift

@@ -277,6 +277,9 @@ public final class SyncCoordinator {
 	) -> MessageRecord {
 		let toJson = encodeAddresses(envelope.to)
 		let ccJson = encodeAddresses(envelope.cc)
+		// Decode RFC 2047 encoded words in subject and sender name
+		let decodedSubject = envelope.subject.map { RFC2047Decoder.decode($0) }
+		let decodedFromName = envelope.from?.name.map { RFC2047Decoder.decode($0) }
 		return MessageRecord(
 			id: UUID().uuidString,
 			accountId: accountId,
@@ -285,9 +288,9 @@ public final class SyncCoordinator {
 			messageId: envelope.messageId,
 			inReplyTo: envelope.inReplyTo,
 			refs: envelope.references,
-			subject: envelope.subject,
+			subject: decodedSubject,
 			fromAddress: envelope.from?.address,
-			fromName: envelope.from?.name,
+			fromName: decodedFromName,
 			toAddresses: toJson,
 			ccAddresses: ccJson,
 			date: envelope.date,