fix: address SQL feature code review findings

- Normalize student SQL to end with exactly one semicolon before
  appending the trailing SELECT, so a missing trailing ; no longer
  produces a confusing parse error (sqlTable.ts)
- Remove unused description field from SqlTablePreset and all presets
  (dead data, nothing in the UI reads it)
- Clear output when the candidate table selection changes, so stale
  results from the previous table don't linger (SqlSection.vue)
- Remove stray console.log(props.language) debug statement
  (CodeEditor.vue)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/components/CodeEditor.vue

@@ -65,7 +65,6 @@ const langExtension = computed(() => {
 })
 
 const enhanceAutoCompletion = computed(() => {
-  console.log(props.language)
   return autocompletion({
     override: [enhanceCompletion(props.language), completeAnyWord],
   })

src/composables/sqlTable.ts

@@ -11,5 +11,6 @@ export function buildSqlScript(studentSql: string) {
   const table =
     sqlTables.find((item) => item.id === selectedTableId.value) ??
     sqlTables[0]
-  return `${table.setupSql}\n\n${studentSql}\n\nSELECT * FROM ${table.tableName};`
+  const normalizedSql = studentSql.trim().replace(/;?\s*$/, ";")
+  return `${table.setupSql}\n\n${normalizedSql}\n\nSELECT * FROM ${table.tableName};`
 }

src/data/sqlTables.ts

@@ -1,7 +1,6 @@
 export interface SqlTablePreset {
   id: string
   label: string
-  description: string
   tableName: string
   setupSql: string
 }
@@ -63,21 +62,18 @@ export const sqlTables: SqlTablePreset[] = [
   {
     id: "students",
     label: "学生成绩表",
-    description: "适合练习按分数筛选、批量更新、删除不及格记录",
     tableName: "students",
     setupSql: studentsSetupSql,
   },
   {
     id: "employees",
     label: "员工工资表",
-    description: "适合练习按部门分组调薪、按入职日期筛选",
     tableName: "employees",
     setupSql: employeesSetupSql,
   },
   {
     id: "products",
     label: "商品库存表",
-    description: "适合练习新增商品、调整库存、下架缺货商品",
     tableName: "products",
     setupSql: productsSetupSql,
   },

src/desktop/SqlSection.vue

@@ -1,6 +1,7 @@
 <script lang="ts" setup>
-import { computed } from "vue"
+import { computed, watch } from "vue"
 import CodeEditor from "../components/CodeEditor.vue"
+import { output } from "../composables/code"
 import { selectedTableId } from "../composables/sqlTable"
 import { sqlTables } from "../data/sqlTables"
 import OutputSection from "./OutputSection.vue"
@@ -10,6 +11,10 @@ const selectedTable = computed(
     sqlTables.find((table) => table.id === selectedTableId.value) ??
     sqlTables[0],
 )
+
+watch(selectedTableId, () => {
+  output.value = ""
+})
 </script>
 
 <template>