refactor(assistant): replace JSON LIKE handling with JSON contains logic

- Updated GetAssistants and DeleteAssistants methods to utilize jsonContainsValue for filtering tags and locales, improving query compatibility across database drivers.
- Renamed related test functions to reflect the new JSON handling approach.
- Removed deprecated jsonLikeExpr and whereJsonLike methods to streamline codebase.

agent/store/xun/assistant.go

@@ -319,8 +319,12 @@ func (store *Xun) GetAssistants(filter types.AssistantFilter, locale ...string)
 	if len(filter.Tags) > 0 {
 		qb.Where(func(qb query.Query) {
 			for i, tag := range filter.Tags {
-				pattern := fmt.Sprintf("%%\"%s\"%%", tag)
-				store.whereJsonLike(qb, "tags", pattern, i > 0)
+				val := store.jsonContainsValue(fmt.Sprintf("%%\"%s\"%%", tag))
+				if i == 0 {
+					qb.WhereJSONContains("tags", val)
+				} else {
+					qb.OrWhereJSONContains("tags", val)
+				}
 			}
 		})
 	}
@@ -332,7 +336,8 @@ func (store *Xun) GetAssistants(filter types.AssistantFilter, locale ...string)
 			qb.Where("name", "like", kw).
 				OrWhere("description", "like", kw).
 				OrWhere("capabilities", "like", kw)
-			store.whereJsonLike(qb, "locales", kw, true)
+			localeVal := store.jsonContainsValue(kw)
+			qb.OrWhereJSONContains("locales", localeVal)
 		})
 	}
 
@@ -708,8 +713,12 @@ func (store *Xun) DeleteAssistants(filter types.AssistantFilter) (int64, error)
 	if len(filter.Tags) > 0 {
 		qb.Where(func(qb query.Query) {
 			for i, tag := range filter.Tags {
-				pattern := fmt.Sprintf("%%\"%s\"%%", tag)
-				store.whereJsonLike(qb, "tags", pattern, i > 0)
+				val := store.jsonContainsValue(fmt.Sprintf("%%\"%s\"%%", tag))
+				if i == 0 {
+					qb.WhereJSONContains("tags", val)
+				} else {
+					qb.OrWhereJSONContains("tags", val)
+				}
 			}
 		})
 	}
@@ -900,6 +909,9 @@ func (store *Xun) translate(model *types.AssistantModel, assistantID string, loc
 
 // sandboxRawSQL returns dialect-specific raw SQL fragments for sandbox JSON null detection.
 // Returns (notNullExpr, isNullExpr) for filtering sandbox field.
+// WhereRaw is used here because this is a JSON literal `null` comparison, not a JSON array
+// contains query. Each dialect requires different casting to compare the JSON value as text.
+// No bind parameters are needed (pure string comparison), so no placeholder issues.
 func (store *Xun) sandboxRawSQL() (string, string) {
 	switch store.getDriver() {
 	case "postgres":

agent/store/xun/xun.go

@@ -2,6 +2,7 @@ package xun
 
 import (
 	"fmt"
+	"strings"
 	"time"
 
 	jsoniter "github.com/json-iterator/go"
@@ -198,33 +199,13 @@ func (store *Xun) getDriver() string {
 	return "mysql"
 }
 
-// jsonLikeExpr returns a dialect-specific SQL expression for LIKE on a JSON column.
-// PostgreSQL requires casting json/jsonb to text before applying LIKE.
-func (store *Xun) jsonLikeExpr(column string) string {
-	switch store.getDriver() {
-	case "postgres":
-		return fmt.Sprintf(`"%s"::text LIKE ?`, column)
-	default:
-		return column + " LIKE ?"
-	}
-}
-
-// whereJsonLike applies a LIKE condition on a JSON column with proper dialect handling.
-func (store *Xun) whereJsonLike(qb query.Query, column, pattern string, or bool) {
-	if store.getDriver() == "postgres" {
-		expr := fmt.Sprintf(`"%s"::text LIKE ?`, column)
-		if or {
-			qb.OrWhereRaw(expr, pattern)
-		} else {
-			qb.WhereRaw(expr, pattern)
-		}
-	} else {
-		if or {
-			qb.OrWhere(column, "like", pattern)
-		} else {
-			qb.Where(column, "like", pattern)
-		}
+// jsonContainsValue formats a value for WhereJSONContains.
+// PG/MySQL need JSON string (e.g. `"tag"`), SQLite needs LIKE pattern (e.g. `%"tag"%`).
+func (store *Xun) jsonContainsValue(value string) string {
+	if store.getDriver() == "sqlite3" {
+		return value
 	}
+	return strings.TrimSuffix(strings.TrimPrefix(value, "%"), "%")
 }
 
 // GenerateAssistantID generates a random-looking 6-digit ID

agent/store/xun/xun_internal_test.go

@@ -81,7 +81,7 @@ func TestSandboxRawSQLAllDialects(t *testing.T) {
 	assert.Contains(t, isNull, "=")
 }
 
-func TestJsonLikeExpr(t *testing.T) {
+func TestJsonContainsValue(t *testing.T) {
 	test.Prepare(t, config.Conf)
 	defer test.Clean()
 
@@ -89,22 +89,20 @@ func TestJsonLikeExpr(t *testing.T) {
 	assert.NoError(t, err)
 	xunStore := store.(*Xun)
 
-	expr := xunStore.jsonLikeExpr("tags")
-	assert.Contains(t, expr, "LIKE ?")
-
 	driver := xunStore.getDriver()
+	val := xunStore.jsonContainsValue(`%"admin"%`)
 	switch driver {
-	case "postgres":
-		assert.Contains(t, expr, `"tags"::text`)
+	case "sqlite3":
+		assert.Equal(t, `%"admin"%`, val, "SQLite keeps LIKE pattern as-is")
 	default:
-		assert.Equal(t, "tags LIKE ?", expr)
+		assert.Equal(t, `"admin"`, val, "PG/MySQL strips % wrappers for JSON value")
 	}
 }
 
-func TestJsonLikeExprFallback(t *testing.T) {
+func TestJsonContainsValueFallback(t *testing.T) {
 	store := &Xun{}
-	expr := store.jsonLikeExpr("tags")
-	assert.Equal(t, "tags LIKE ?", expr)
+	val := store.jsonContainsValue(`%"test"%`)
+	assert.Equal(t, `"test"`, val, "Default (mysql) strips % wrappers")
 }
 
 func TestToDBTime(t *testing.T) {