add partial index for patient number

cmd/main-migration/migrations/atlas.sum

@@ -1,4 +1,4 @@
-h1:MO6ze6e6ClW/WxUyiZxT6Lmhz8BDgXmmYeLDSN4xEJw=
+h1:DgMML95zGYI7JMvZaIb/gySCvncMu62CANOIXNX0A6w=
 20250904105930.sql h1:MEM6blCgke9DzWQSTnLzasbPIrcHssNNrJqZpSkEo6k=
 20250904141448.sql h1:J8cmYNk4ZrG9fhfbi2Z1IWz7YkfvhFqTzrLFo58BPY0=
 20250908062237.sql h1:Pu23yEW/aKkwozHoOuROvHS/GK4ngARJGdO7FB7HZuI=
@@ -143,4 +143,4 @@ h1:MO6ze6e6ClW/WxUyiZxT6Lmhz8BDgXmmYeLDSN4xEJw=
 20251202130629.sql h1:9mvalqfhqGCdkcJepJDzHprU2xb0i5sYys1Htf62ioo=
 20251202160848.sql h1:Kd2/TziKSMezrt4XgbjQcYvY/Lo9rX0qw7/Lz0/oyKk=
 20251202180207.sql h1:IHmSMIO3ia+YV5GULixbdlV1joaUAWtnjQHPd8+HKiM=
-20251202231005.sql h1:iVzsqbqmfncDXPPXoRqCQdcvgvLBv57TbzdbzQAmSVc=
+20251202231005.sql h1:lua0KKoeBptSfs/6ehZE6Azo6YUlNkOJwGFyb1HQWkY=

internal/domain/main-entities/patient/entity.go

@@ -15,7 +15,14 @@ type Patient struct {
 	RegisteredAt           *time.Time           `json:"registeredAt"`
 	RegisteredBy_User_Name *string              `json:"registeredBy_user_name" gorm:"size:100"`
 	Status_Code            erc.ActiveStatusCode `json:"status_code" gorm:"not null;size:10"`
-	Number                 *string              `json:"number" gorm:"unique;size:15"`
-	Parent_Number          *string              `json:"parent_number"`
-	Parent                 *Patient             `json:"parent,omitempty" gorm:"foreignKey:Parent_Number;references:Number"`
+
+	// Normal UNIQUE index — required for the foreign key reference
+	Number *string `json:"number" gorm:"size:15;unique"`
+
+	// Partial unique index — keeps Number unique only for non–soft-deleted records.
+	// Allows duplicate Number values when previous records are soft-deleted.
+	_ struct{} `gorm:"uniqueIndex:idx_number_active,where:\"DeletedAt\" IS NULL"`
+
+	Parent_Number *string  `json:"parent_number"`
+	Parent        *Patient `json:"parent,omitempty" gorm:"foreignKey:Parent_Number;references:Number"`
 }