feat(api): implement personalities CRUD API (#537)

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

apps/api/src/personalities/entities/personality.entity.ts

@@ -1,20 +1,24 @@
-import type { Personality as PrismaPersonality } from "@prisma/client";
+import type { FormalityLevel } from "@prisma/client";
 
 /**
- * Personality entity representing an assistant configuration
+ * Personality response entity
+ * Maps Prisma Personality fields to the frontend API contract.
+ *
+ * Field mapping (Prisma -> API):
+ *   systemPrompt   -> systemPromptTemplate
+ *   isEnabled      -> isActive
+ *   (tone, formalityLevel are identical in both)
  */
-export class Personality implements PrismaPersonality {
-  id!: string;
-  workspaceId!: string;
-  name!: string; // unique identifier slug
-  displayName!: string; // human-readable name
-  description!: string | null;
-  systemPrompt!: string;
-  temperature!: number | null; // null = use provider default
-  maxTokens!: number | null; // null = use provider default
-  llmProviderInstanceId!: string | null; // FK to LlmProviderInstance
-  isDefault!: boolean;
-  isEnabled!: boolean;
-  createdAt!: Date;
-  updatedAt!: Date;
+export interface PersonalityResponse {
+  id: string;
+  workspaceId: string;
+  name: string;
+  description: string | null;
+  tone: string;
+  formalityLevel: FormalityLevel;
+  systemPromptTemplate: string;
+  isDefault: boolean;
+  isActive: boolean;
+  createdAt: Date;
+  updatedAt: Date;
 }