feat(type_mapper): add support for serial types and auto-increment tags

pkg/writers/bun/writer_test.go

@@ -90,8 +90,8 @@ func TestWriter_WriteTable(t *testing.T) {
 	}
 
 	// Verify Bun-specific elements
-	if !strings.Contains(generated, "bun:\"id,type:bigint,pk,") {
-		t.Errorf("Missing Bun-style primary key tag")
+	if !strings.Contains(generated, "bun:\"id,type:bigint,pk,autoincrement,") {
+		t.Errorf("Missing Bun-style primary key tag with autoincrement")
 	}
 }
 
@@ -624,6 +624,37 @@ func TestTypeMapper_BuildBunTag(t *testing.T) {
 			},
 			want: []string{"status,", "type:text,", "default:active,"},
 		},
+		{
+			name: "auto increment with AutoIncrement flag",
+			column: &models.Column{
+				Name:          "id",
+				Type:          "bigint",
+				NotNull:       true,
+				IsPrimaryKey:  true,
+				AutoIncrement: true,
+			},
+			want: []string{"id,", "type:bigint,", "pk,", "autoincrement,"},
+		},
+		{
+			name: "serial type (auto-increment)",
+			column: &models.Column{
+				Name:         "id",
+				Type:         "serial",
+				NotNull:      true,
+				IsPrimaryKey: true,
+			},
+			want: []string{"id,", "type:serial,", "pk,", "autoincrement,"},
+		},
+		{
+			name: "bigserial type (auto-increment)",
+			column: &models.Column{
+				Name:         "id",
+				Type:         "bigserial",
+				NotNull:      true,
+				IsPrimaryKey: true,
+			},
+			want: []string{"id,", "type:bigserial,", "pk,", "autoincrement,"},
+		},
 	}
 
 	for _, tt := range tests {