feat(office): mail preview, infinite scroll, pane resize, and scrollbars

Polish the office TUI with proportional pane layout, drag resize, live
filtering, HTML mail preview, paginated mail lists, overflow scrollbars,
flattened navigation, and project save/status fixes; add UpdateProjectStatus.

Co-authored-by: Cursor <cursoragent@cursor.com>

cmd/office/preview/entity.go

@@ -42,25 +42,71 @@ func OpportunityMarkdown(m map[string]any) string {
 	return strings.TrimSpace(b.String()) + "\n"
 }
 
-// MailMarkdown formats a mail message for preview.
+// MailMarkdown formats a mail message for terminal preview (HTML body is converted to markdown).
 func MailMarkdown(m map[string]any) string {
 	var b strings.Builder
 	fmt.Fprintf(&b, "# %s\n\n", str(m, "subject"))
-	fmt.Fprintf(&b, "**From:** %s\n\n", str(m, "from"))
-	if to := str(m, "to"); to != "" {
+	fmt.Fprintf(&b, "**From:** %s\n\n", mailAddressLine(m, "from"))
+	if to := mailAddressLine(m, "to"); to != "" {
 		fmt.Fprintf(&b, "**To:** %s\n\n", to)
 	}
-	body := str(m, "body")
-	if body == "" {
-		body = str(m, "htmlBody")
+	if cc := mailAddressLine(m, "cc"); cc != "" {
+		fmt.Fprintf(&b, "**Cc:** %s\n\n", cc)
 	}
-	body = stripHTML(body)
-	if body != "" {
-		fmt.Fprintf(&b, "## Body\n\n%s\n\n", body)
+	if date := str(m, "date"); date != "" {
+		fmt.Fprintf(&b, "**Date:** %s\n\n", date)
+	}
+	if body := mailBodyMarkdown(m); body != "" {
+		fmt.Fprintf(&b, "---\n\n%s\n", body)
 	}
 	return strings.TrimSpace(b.String()) + "\n"
 }
 
+func mailAddressLine(m map[string]any, key string) string {
+	if v := str(m, key); v != "" {
+		return v
+	}
+	name := str(m, key+"Name")
+	addr := str(m, key+"Address")
+	switch {
+	case name != "" && addr != "":
+		return fmt.Sprintf("%s <%s>", name, addr)
+	case addr != "":
+		return addr
+	default:
+		return name
+	}
+}
+
+func mailBodyMarkdown(m map[string]any) string {
+	htmlBody := strings.TrimSpace(str(m, "htmlBody"))
+	plainBody := strings.TrimSpace(str(m, "body"))
+
+	for _, candidate := range []string{htmlBody, plainBody} {
+		if candidate == "" {
+			continue
+		}
+		if looksLikeHTML(candidate) {
+			if md, err := HTMLToMarkdown(candidate); err == nil {
+				if md = strings.TrimSpace(md); md != "" {
+					return md
+				}
+			}
+		}
+	}
+	if plainBody != "" {
+		return plainBody
+	}
+	if htmlBody != "" {
+		return stripHTML(htmlBody)
+	}
+	return ""
+}
+
+func looksLikeHTML(s string) bool {
+	return strings.Contains(s, "<") && strings.Contains(s, ">") && htmlTagRe.MatchString(s)
+}
+
 // EventMarkdown formats a calendar event for preview.
 func EventMarkdown(m map[string]any) string {
 	var b strings.Builder