Add backend foundation and config-driven workbench

backend/scripts/start-dev.ps1

@@ -0,0 +1,29 @@
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+
+$scriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
+$backendDir = Split-Path -Parent $scriptDir
+
+Set-Location $backendDir
+
+$env:APP_ENV = if ($env:APP_ENV) { $env:APP_ENV } else { "development" }
+$env:HTTP_ADDR = if ($env:HTTP_ADDR) { $env:HTTP_ADDR } else { ":18090" }
+$env:DATABASE_URL = if ($env:DATABASE_URL) { $env:DATABASE_URL } else { "postgres://postgres:asdf*123@192.168.100.77:5432/cmr20260401?sslmode=disable" }
+$env:JWT_ACCESS_SECRET = if ($env:JWT_ACCESS_SECRET) { $env:JWT_ACCESS_SECRET } else { "change-me-in-production" }
+$env:AUTH_SMS_PROVIDER = if ($env:AUTH_SMS_PROVIDER) { $env:AUTH_SMS_PROVIDER } else { "console" }
+$env:WECHAT_MINI_DEV_PREFIX = if ($env:WECHAT_MINI_DEV_PREFIX) { $env:WECHAT_MINI_DEV_PREFIX } else { "dev-" }
+
+Write-Host "CMR backend dev server" -ForegroundColor Cyan
+Write-Host ("APP_ENV=" + $env:APP_ENV)
+Write-Host ("HTTP_ADDR=" + $env:HTTP_ADDR)
+Write-Host ("DATABASE_URL=" + $env:DATABASE_URL)
+Write-Host ""
+Write-Host "Workbench:" -ForegroundColor Yellow
+$workbenchAddr = $env:HTTP_ADDR
+if ($workbenchAddr.StartsWith(":")) {
+  $workbenchAddr = "127.0.0.1" + $workbenchAddr
+}
+Write-Host ("http://" + $workbenchAddr + "/dev/workbench")
+Write-Host ""
+
+go run .\cmd\api