feat(api): add conversation archive with vector search (MS22-DB-004, MS22-API-004) (#587)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/api/src/conversation-archive/dto/list-conversations.dto.ts

@@ -0,0 +1,33 @@
+import { IsString, IsOptional, MaxLength, IsInt, Min, Max, IsDateString } from "class-validator";
+import { Type } from "class-transformer";
+
+/**
+ * DTO for listing/filtering conversation archives
+ */
+export class ListConversationsDto {
+  @IsOptional()
+  @IsString()
+  @MaxLength(500)
+  agentId?: string;
+
+  @IsOptional()
+  @IsDateString()
+  startedAfter?: string;
+
+  @IsOptional()
+  @IsDateString()
+  startedBefore?: string;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt()
+  @Min(1)
+  page?: number;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt()
+  @Min(1)
+  @Max(100)
+  limit?: number;
+}