Replace inline type annotations with proper class-validator DTOs for the semantic and hybrid search endpoints. Adds SemanticSearchBodyDto, HybridSearchBodyDto (query: @IsString @MaxLength(500), status: @IsOptional @IsEnum(EntryStatus)), and SemanticSearchQueryDto (page/limit with @IsInt @Min/@Max validation). Includes 22 new tests covering DTO validation edge cases and controller integration. Co-Authored-By: Claude Opus 4.6 <[email protected]>