feat(BE-47,48,49,50): implement inventory adjustment system

- Extend DB schema with product_warehouses and stock_logs tables
- Implement stock adjustment API (increase/decrease operations)
- Add comprehensive validation for all adjustment operations
- Implement audit log system for each adjustment with history tracking
- Include transaction handling, DTOs, seeders, and proper error handling
- Add adjustment history API with pagination and filtering

TODO: Integration testing pending

internal/entities/adjustment.go

@@ -1,18 +0,0 @@
-package entities
-
-import (
-	"time"
-
-	"gorm.io/gorm"
-)
-
-type Adjustment struct {
-	Id        uint           `gorm:"primaryKey"`
-	Name      string         `gorm:"not null;uniqueIndex:idx_name,where:deleted_at IS NULL"`
-	CreatedBy uint           `gorm:"not null"`
-	CreatedAt time.Time      `gorm:"autoCreateTime"`
-	UpdatedAt time.Time      `gorm:"autoUpdateTime"`
-	DeletedAt gorm.DeletedAt `gorm:"index" json:"-"`
-
-	CreatedUser User `gorm:"foreignKey:CreatedBy;references:Id"`
-}

internal/entities/product_warehouse.go

@@ -10,7 +10,7 @@ type ProductWarehouse struct {
 	Id          uint           `json:"id" gorm:"primaryKey;autoIncrement"`
 	ProductId   uint           `json:"product_id" gorm:"not null"`
 	WarehouseId uint           `json:"warehouse_id" gorm:"not null"`
-	Quantity    int            `json:"quantity" gorm:"default:0"`
+	Quantity    float64            `json:"quantity" gorm:"default:0"`
 	CreatedAt   time.Time      `json:"created_at" gorm:"autoCreateTime"`
 	UpdatedAt   time.Time      `json:"updated_at" gorm:"autoUpdateTime"`
 	CreatedBy   uint           `json:"created_by" gorm:"not null"`

internal/entities/stock_log.go

@@ -6,23 +6,30 @@ import (
 	"gorm.io/gorm"
 )
 
+const (
+	LogTypeAdjustment = "ADJUSTMENT"
+)
+
+const (
+	TransactionTypeIncrease = "INCREASE"
+	TransactionTypeDecrease = "DECREASE"
+)
+
 type StockLog struct {
-	Id                 uint           `json:"id" gorm:"primaryKey;"`
-	TransactionType    string         `json:"transaction_type" gorm:"type:varchar(20);not null"`
-	Quantity           float64        `json:"quantity" gorm:"type:numeric(15,3);not null"`
-	BeforeQuantity     float64        `json:"before_quantity" gorm:"type:numeric(15,3);not null"`
-	AfterQuantity      float64        `json:"after_quantity" gorm:"type:numeric(15,3);not null"`
-	LogType            string         `json:"log_type" gorm:"type:varchar(50);not null"`
-	LogId              uint           `json:"log_id" gorm:"not null"`
-	Note               string         `json:"note" gorm:"type:text"`
-	ProductWarehouseId uint           `json:"product_warehouse_id" gorm:"not null;index"`
-	CreatedBy          uint           `json:"created_by" gorm:"not null;index"`
-	CreatedAt          time.Time      `json:"created_at" gorm:"autoCreateTime"`
-	UpdatedAt          time.Time      `json:"updated_at" gorm:"autoUpdateTime"`
-	DeletedAt          gorm.DeletedAt `json:"deleted_at" gorm:"index"`
+	Id                 uint           `json:"id" gorm:"primaryKey;column:id"`
+	TransactionType    string         `json:"transaction_type" gorm:"column:transaction_type;type:varchar(20);not null"`
+	Quantity           float64        `json:"quantity" gorm:"column:quantity;type:numeric(15,3);not null"`
+	BeforeQuantity     float64        `json:"before_quantity" gorm:"column:before_quantity;type:numeric(15,3);not null"`
+	AfterQuantity      float64        `json:"after_quantity" gorm:"column:after_quantity;type:numeric(15,3);not null"`
+	LogType            string         `json:"log_type" gorm:"column:log_type;type:varchar(50);not null;index:stock_logs_flaggable_lookup,priority:1"`
+	LogId              uint           `json:"log_id" gorm:"column:log_id;not null;index:stock_logs_flaggable_lookup,priority:2"`
+	Note               string         `json:"note" gorm:"column:note;type:text"`
+	ProductWarehouseId uint           `json:"product_warehouse_id" gorm:"column:product_warehouse_id;not null;index"`
+	CreatedBy          uint           `json:"created_by" gorm:"column:created_by;not null;index"`
+	CreatedAt          time.Time      `json:"created_at" gorm:"column:created_at;autoCreateTime"`
+	UpdatedAt          time.Time      `json:"updated_at" gorm:"column:updated_at;autoUpdateTime"`
+	DeletedAt          gorm.DeletedAt `json:"deleted_at,omitempty" gorm:"column:deleted_at;index"`
 
 	ProductWarehouse *ProductWarehouse `json:"product_warehouse,omitempty" gorm:"foreignKey:ProductWarehouseId;references:Id"`
 	CreatedUser      *User             `json:"created_user,omitempty" gorm:"foreignKey:CreatedBy;references:Id"`
 }
-
-