feat(api): add findings module with vector search (MS22-DB-001, MS22-API-001) (#585)

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

apps/api/src/findings/dto/search-findings.dto.ts

@@ -0,0 +1,52 @@
+import { Type } from "class-transformer";
+import {
+  IsInt,
+  IsNumber,
+  IsOptional,
+  IsString,
+  IsUUID,
+  Max,
+  MaxLength,
+  Min,
+} from "class-validator";
+
+/**
+ * DTO for finding semantic similarity search
+ */
+export class SearchFindingsDto {
+  @IsString({ message: "query must be a string" })
+  @MaxLength(1000, { message: "query must not exceed 1000 characters" })
+  query!: string;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt({ message: "page must be an integer" })
+  @Min(1, { message: "page must be at least 1" })
+  page?: number;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt({ message: "limit must be an integer" })
+  @Min(1, { message: "limit must be at least 1" })
+  @Max(100, { message: "limit must not exceed 100" })
+  limit?: number;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsNumber({}, { message: "similarityThreshold must be a number" })
+  @Min(0, { message: "similarityThreshold must be at least 0" })
+  @Max(1, { message: "similarityThreshold must not exceed 1" })
+  similarityThreshold?: number;
+
+  @IsOptional()
+  @IsString({ message: "agentId must be a string" })
+  agentId?: string;
+
+  @IsOptional()
+  @IsString({ message: "type must be a string" })
+  type?: string;
+
+  @IsOptional()
+  @IsUUID("4", { message: "taskId must be a valid UUID" })
+  taskId?: string;
+}