feat: add email result and search filter models

Add EmailResult class for holding email search results with
subject, sender, date, body preview, attachments, and metadata.
Add SearchFilters for encapsulating search criteria.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

EmailSearch/EmailResult.cs

@@ -0,0 +1,58 @@
+using NetOffice.OutlookApi;
+
+public class EmailResult
+{
+    public string Subject { get; set; } = "";
+    public string Sender { get; set; } = "";
+    public string CC { get; set; } = "";
+    public string BCC { get; set; } = "";
+    public DateTime ReceivedDate { get; set; }
+    public string BodyPreview { get; set; } = "";
+    public string Folder { get; set; } = "";
+    public int AttachmentCount { get; set; }
+    public string AttachmentNames { get; set; } = "";
+    public string Importance { get; set; } = "";
+    public string Categories { get; set; } = "";
+    public string FlagStatus { get; set; } = "";
+
+    public static EmailResult FromMailItem(MailItem mail, string folderName)
+    {
+        var bodyPreview = TruncatePreview(mail.Body ?? "", 300);
+        var attachmentNames = GetAttachmentNames(mail);
+
+        return new EmailResult
+        {
+            Subject = mail.Subject ?? "(No Subject)",
+            Sender = $"{mail.SenderName} <{mail.SenderEmailAddress}>",
+            CC = mail.CC ?? "",
+            BCC = mail.BCC ?? "",
+            ReceivedDate = mail.ReceivedTime,
+            BodyPreview = bodyPreview,
+            Folder = folderName,
+            AttachmentCount = attachmentNames.Count,
+            AttachmentNames = string.Join(", ", attachmentNames),
+            Importance = mail.Importance.ToString().Replace("olImportance", ""),
+            Categories = mail.Categories ?? "",
+            FlagStatus = mail.FlagStatus.ToString().Replace("olFlag", "").Replace("olNo", "Not")
+        };
+    }
+
+    private static string TruncatePreview(string body, int maxLength)
+    {
+        var preview = body;
+        if (preview.Length > maxLength)
+            preview = preview.Substring(0, maxLength) + "...";
+        return preview.Replace("\r\n", " ").Replace("\n", " ").Trim();
+    }
+
+    private static List<string> GetAttachmentNames(MailItem mail)
+    {
+        var names = new List<string>();
+        foreach (var attachment in mail.Attachments)
+        {
+            if (attachment is Attachment att)
+                names.Add(att.FileName);
+        }
+        return names;
+    }
+}

EmailSearch/SearchFilters.cs

@@ -0,0 +1,12 @@
+using NetOffice.OutlookApi.Enums;
+
+public class SearchFilters
+{
+    public string? Keywords { get; set; }
+    public string? Sender { get; set; }
+    public string? Subject { get; set; }
+    public string? HasAttachment { get; set; }
+    public OlImportance? Importance { get; set; }
+    public string? Category { get; set; }
+    public OlFlagStatus? FlagStatus { get; set; }
+}