fix(evolution): resolve pgvector type conflict in SystemExperienceORM

The embedding column was declared as float[] but the database uses
VECTOR(1536) from pgvector. TypeORM doesn't natively support pgvector
types, causing 500 errors when querying the system_experiences table.

Fixed by:
- Changed column type to 'text' with select: false
- This prevents TypeORM from trying to select/map the vector column
- The embedding field is only used for similarity searches via raw SQL

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/services/evolution-service/src/infrastructure/database/entities/system-experience.orm.ts

@@ -47,8 +47,9 @@ export class SystemExperienceORM {
   @Column({ name: 'negative_count', default: 0 })
   negativeCount: number;
 
-  @Column('float', { array: true, nullable: true })
-  embedding: number[];
+  // pgvector VECTOR(1536) - exclude from default selects to avoid type conflicts
+  @Column({ type: 'text', name: 'embedding', nullable: true, select: false })
+  embedding: string;
 
   @Column({ name: 'is_active', default: false })
   isActive: boolean;