feat(search): fuzzy/typo tolerance (pg_trgm) (#16)

src/InboxIntel.Application/DTOs/EmailDtos.cs

@@ -2,6 +2,13 @@ using InboxIntel.Domain.Enums;
 
 namespace InboxIntel.Application.DTOs;
 
+/// <summary>
+/// Row summary for search/list results. <c>MatchHighlight</c> is a "why this matched" body
+/// fragment (ts_headline) with matched terms wrapped in U+E000/U+E001 sentinels — NOT HTML;
+/// the client renders them as escaped &lt;mark&gt; elements, so untrusted email content can
+/// never inject markup. Null unless the search had a free-text query; optional/last so other
+/// DTO constructors are unaffected.
+/// </summary>
 public record EmailSummaryDto(
     Guid Id,
     string GmailMessageId,
@@ -17,10 +24,6 @@ public record EmailSummaryDto(
     EmailCategory Category,
     bool HasListUnsubscribe,
     bool SupportsOneClick,
-    // "Why this matched": a ts_headline fragment of the body with matched terms wrapped in
-    // U+E000/U+E001 sentinels (NOT HTML — the client renders them as escaped <mark> elements,
-    // so untrusted email content can never inject markup). Null unless the search had a
-    // free-text query. Optional/last so other DTO constructors are unaffected.
     string? MatchHighlight = null);
 
 /// <summary>Full single-email view, including body text, for the detail pane.</summary>