app #0: cube.famzheng.me 入口门户 + 平台脚手架

monorepo 第一刀：
- workspace + crates/cube-core（base router / healthz / ServeDir SPA fallback / JSON tracing / SIGTERM shutdown）
- apps/cube：axum 主程序 + Vite + Vue 3 + TS 门户（暗色调 + 渐变 logo + app 卡片网格）
- Dockerfile：scratch + musl 静态二进制，镜像 2.6MB
- k8s/：cube-cube ns + Deployment + Service + Ingress（cube.famzheng.me，traefik LE 自动签）
- registry：新增 registry.famzheng.me ingress 反代到 gitea 内置 container registry，
  自动化身份用 mochi（registry.famzheng.me/mochi/cube）
- CI：.gitea/workflows/deploy-cube.yml，host shell runner（gnoc），
  build → push → kubectl rollout 五步流水
- README：把宪法段改成 monorepo 模式 + monorepo 目录结构
- 新增宪法条款：前端视图状态走 URL（path + query）保证可 bookmark

Cargo.toml

@@ -0,0 +1,26 @@
+[workspace]
+resolver = "2"
+members = [
+    "crates/cube-core",
+    "apps/cube",
+]
+
+[workspace.package]
+edition = "2021"
+license = "MIT"
+authors = ["Fam Zheng <fam@euphon.net>"]
+
+[workspace.dependencies]
+axum = "0.7"
+tokio = { version = "1", features = ["full"] }
+tower = "0.5"
+tower-http = { version = "0.6", features = ["fs", "trace"] }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
+
+[profile.release]
+opt-level = "z"
+lto = true
+codegen-units = 1
+strip = true
+panic = "abort"