feat(behavior): implement CreateBehaviorLogDto (#338)

backend/src/modules/behavior/dto/create-behavior-log.dto.ts

@@ -0,0 +1,89 @@
+import {
+  IsUUID,
+  IsString,
+  IsNotEmpty,
+  IsEnum,
+  IsOptional,
+  IsInt,
+  Min,
+  Max,
+  MaxLength,
+  IsDateString,
+} from 'class-validator';
+
+export enum BehaviorType {
+  AGGRESSION = 'aggression',
+  ANXIETY = 'anxiety',
+  APPETITE_CHANGE = 'appetite_change',
+  ENERGY_LEVEL = 'energy_level',
+  GROOMING = 'grooming',
+  LETHARGY = 'lethargy',
+  SOCIALIZATION = 'socialization',
+  TRAINING = 'training',
+  OTHER = 'other',
+}
+
+export enum BehaviorSeverity {
+  LOW = 'low',
+  MEDIUM = 'medium',
+  HIGH = 'high',
+  CRITICAL = 'critical',
+}
+
+/**
+ * DTO for creating a new behavior log entry.
+ *
+ * @example
+ * {
+ *   "petId": "550e8400-e29b-41d4-a716-446655440000",
+ *   "behaviorType": "aggression",
+ *   "description": "Growled at another dog during walk",
+ *   "severity": "medium",
+ *   "notes": "Occurred near the park entrance",
+ *   "observedAt": "2026-05-27T10:00:00Z"
+ * }
+ */
+export class CreateBehaviorLogDto {
+  /** UUID of the pet this behavior log belongs to. */
+  @IsUUID()
+  petId: string;
+
+  /** Categorized behavior type. */
+  @IsEnum(BehaviorType)
+  behaviorType: BehaviorType;
+
+  /** Human-readable description of the observed behavior. */
+  @IsString()
+  @IsNotEmpty()
+  @MaxLength(1000)
+  description: string;
+
+  /** Optional severity level of the behavior. */
+  @IsOptional()
+  @IsEnum(BehaviorSeverity)
+  severity?: BehaviorSeverity;
+
+  /**
+   * Optional intensity score on a 1–10 scale.
+   * Useful for tracking trends over time.
+   */
+  @IsOptional()
+  @IsInt()
+  @Min(1)
+  @Max(10)
+  intensity?: number;
+
+  /** Optional free-form notes from the observer (vet or owner). */
+  @IsOptional()
+  @IsString()
+  @MaxLength(2000)
+  notes?: string;
+
+  /**
+   * ISO-8601 timestamp of when the behavior was observed.
+   * Defaults to the time of record creation if omitted.
+   */
+  @IsOptional()
+  @IsDateString()
+  observedAt?: string;
+}