feat(goauto): suggest color/size specs via AI, human-confirmed save (#172)

Add batch AI suggestion for Shopee color/size spec mapping: a
specContextVersion snapshot guards both the new suggest endpoints and
must be echoed back, short id binding keeps the model from ever
returning a value outside the server-supplied PDD candidates, and
suggestions only prefill the draft above AutoConfirmMinConfidence -
low-confidence answers show the reason but stay unapplied. Every
AI-sourced mapping is still written as pending by the existing
SetMapping rule and needs an explicit operator confirm, same as
before for manual edits.

Server: server/app/goauto/aimatching/suggest.go (batch provider call),
server/app/goauto/shopeeproduct/{context_version,ai_suggest}.go (spec
context version + suggest-colors/suggest-sizes), wired into
handler.go/router.go/service.go.
Web: shopee-products AI 匹配 button on both tabs, low-confidence rows
left for manual pick, pending AI mappings get an explicit 确认 action.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VkjpksKeizaRpYXfgD74Lf

web/src/api/goauto/shopee-products.js

@@ -52,6 +52,14 @@ export function previewShopeeAutoSizeMatches(productId) {
   return request({ url: `/api/admin/v1/shopee-products/${productId}/specs/mapping/preview-auto-size`, method: 'post' })
 }
 
+export function suggestShopeeColorMappings(productId, data) {
+  return request({ url: `/api/admin/v1/shopee-products/${productId}/specs/mapping/suggest-colors`, method: 'post', data })
+}
+
+export function suggestShopeeSizeMappings(productId, data) {
+  return request({ url: `/api/admin/v1/shopee-products/${productId}/specs/mapping/suggest-sizes`, method: 'post', data })
+}
+
 export function batchDeleteShopeeProducts(data) {
   return request({ url: '/api/admin/v1/shopee-products/batch-delete', method: 'post', data })
 }