feat(test): 引入测试规则文档与参数化测试库初始化脚本

对齐 wkbox 衍生项目的测试规则体系，剥离业务特定内容后移植到框架：

- 规则 .agents/rules/ulthon-testing.md（设计哲学/决策树/4层模型/安全规范/fixture原则）
- 技能 .agents/skills/ulthon-testing（运行/编写/模板/决策/回归验证）
- 参数化建库脚本 tests/setup_test_db.{php,ps1,sh} + README
- AGENTS.md 索引补充

与 wkbox 差异：测试库参数化（复用 .env 连接，database=env+'_test'），不硬编码 Docker；删去 canBind Oracle 业务约束与具体 fixture 工厂，业务工厂由衍生项目自行实现。

tests/setup_test_db.ps1

@@ -0,0 +1,46 @@
+<#
+.SYNOPSIS
+    Test database setup (Windows / PowerShell wrapper).
+
+.DESCRIPTION
+    Calls the PHP runner tests/setup_test_db.php, which in a single process:
+      1. reads connection params from .env (hostname/hostport/username/password/
+         charset/prefix/database)
+      2. derives the test DB name as {env.database} + '_test'
+         (e.g. ulthon_admin -> ulthon_admin_test)
+      3. CREATE DATABASE IF NOT EXISTS on the same MySQL instance (no Docker)
+      4. config-level override connections.main -> test DB
+      5. php think migrate:run  -> system/framework tables (database/migrations/)
+      6. php think scheme:sync  -> business tables (app/admin/scheme/)
+      7. php think seed:run     -> reference data (database/seeds/)
+      8. queries information_schema to verify the tables landed in the test DB
+
+    Fully parameterized: no hardcoded host/port/credentials. The MySQL instance
+    is whatever .env points at (typically a single local MySQL).
+
+.NOTES
+    ASCII-only on purpose: PowerShell 5.1 mis-decodes BOM-less UTF-8 CJK.
+#>
+
+# Runner lives next to this script.
+$Runner = Join-Path $PSScriptRoot 'setup_test_db.php'
+
+# 1. Ensure php is on PATH.
+$phpCmd = Get-Command php -ErrorAction SilentlyContinue
+if (-not $phpCmd) {
+    Write-Host "[ERROR] 'php' not found on PATH. Install PHP 8+ and add it to PATH." -ForegroundColor Red
+    exit 1
+}
+
+# 2. Run the PHP runner.
+Write-Host "==== Running setup_test_db.php ====" -ForegroundColor Cyan
+& php $Runner
+$code = $LASTEXITCODE
+
+Write-Host ""
+if ($code -eq 0) {
+    Write-Host "==== Done. PHP exit code = $code ====" -ForegroundColor Green
+} else {
+    Write-Host "==== Done. PHP exit code = $code ====" -ForegroundColor Red
+}
+exit $code