feat: add EmailSummary, ClassificationResult, and ActivityEntry models

src/SpamGuard/Models/ActivityEntry.cs

@@ -0,0 +1,20 @@
+// src/SpamGuard/Models/ActivityEntry.cs
+namespace SpamGuard.Models;
+
+public enum Verdict
+{
+    Trusted,
+    Spam,
+    Legitimate,
+    Uncertain,
+    Error
+}
+
+public sealed record ActivityEntry(
+    DateTime Timestamp,
+    string Sender,
+    string Subject,
+    Verdict Verdict,
+    double? Confidence,
+    string? Reason
+);

src/SpamGuard/Models/ClassificationResult.cs

@@ -0,0 +1,11 @@
+// src/SpamGuard/Models/ClassificationResult.cs
+namespace SpamGuard.Models;
+
+public sealed record ClassificationResult(
+    string Classification,
+    double Confidence,
+    string Reason
+)
+{
+    public bool IsSpam => string.Equals(Classification, "spam", StringComparison.OrdinalIgnoreCase);
+}

src/SpamGuard/Models/EmailSummary.cs

@@ -0,0 +1,10 @@
+// src/SpamGuard/Models/EmailSummary.cs
+namespace SpamGuard.Models;
+
+public sealed record EmailSummary(
+    uint Uid,
+    string From,
+    string Subject,
+    string BodySnippet,
+    DateTimeOffset Date
+);