refactor: frontend TS migration + Tailwind4/daisyUI5 unify + BUILDPLATFORM docker build

- migrate frontend to TypeScript (vue-tsc strict in build), upgrade all deps to latest (Vite 8, Tailwind 4, daisyUI 5, Pinia 4, vue-router 5)
- restructure frontend dirs (api/components/common/layouts/styles/types/views)
- drop Element Plus, add daisyUI TagInput; main CSS 490KB->163KB, entry JS 618KB->1.3KB
- rewrite Dockerfile(.cn): frontend/backend stages pinned to $BUILDPLATFORM, CGO_ENABLED=0 cross-compile, no QEMU in multi-arch builds; add .dockerignore
- local dev: Vite /api proxy + make dev targets; go:embed all:dist with .gitkeep so backend runs without prior frontend build
- fix latent bugs: Keys.vue users ref, Settings.vue undefined userStore, Login.vue Ref-as-error display, res.error misuse
- add REFACTOR_PLAN.md (phased refactor log)

cmd/openteam/main.go

@@ -14,7 +14,9 @@ import (
 	"github.com/spf13/cobra"
 )
 
-//go:embed dist/*
+// all:dist 使 dist 只含 .gitkeep 占位（尚未构建前端）时也能编译通过，
+// 本地 go run ./cmd/openteam 无需先跑 pnpm build
+//go:embed all:dist
 var web embed.FS
 
 func main() {