v0.3.0: 单 sources 入口 + 路径后缀覆盖约定

破坏性重构。框架对外只暴露一个 `sources` glob 入口,消费侧任何 .vue
都按文件路径后缀匹配同后缀覆盖:

- shrimp/components/<name>.vue 同后缀覆盖框架内置(login/layout/topbar/ShrimpTable/...)
- shrimp/components/fields/Field<X>.vue 注册类型 <x>(首字母小写)
- shrimp/module/<key>.vue 业务模块

变更:
- 删除 customFields / moduleSources / overrideField / registerField 旧入口
- 删除 fieldOverrides Map,字段表纯靠 glob 扫描注册
- 框架内 .vue 对可覆盖 peer 改用 defineAsyncComponent(resolveVue(...))
  (login → ShrimpLangSwitch / layout → sideM/navMenu/topbar/userbar/logo /
   ShrimpTable → ShrimpEditDrawer/ShrimpFilterDrawer/...)
- views/ 全部并入 components/,App.vue 上提到 src/ 根
- LangSwitch → ShrimpLangSwitch,PowerTree → ShrimpPowerTree
- module/FieldRelativeTime.vue → components/fields/FieldRelativeTime.vue
- module/user.vue 改用 #column-updatedAt slot 替代旧的 overrideField

字段类型约定从 'field' + Name 改为 lowercase-first(FieldString → 'string'),
内置和消费侧统一。

src/module/user.vue

@@ -1,13 +1,17 @@
 <template>
-    <ShrimpTable moduleKey="user" />
+    <ShrimpTable moduleKey="user">
+        <template #column-updatedAt="{ row }">
+            <FieldRelativeTime :model-value="row.updatedAt" mode="display" :field="{}" />
+        </template>
+    </ShrimpTable>
 </template>
 
 <script lang="ts" setup>
-import ShrimpTable from '../components/ShrimpTable.vue'
-import { vueAdmin } from '../VueAdmin'
-import FieldRelativeTime from './FieldRelativeTime.vue'
+import { defineAsyncComponent } from 'vue'
+import { resolveVue } from '../VueAdmin'
 
-vueAdmin.overrideField('user', 'updatedAt', FieldRelativeTime)
+const ShrimpTable = defineAsyncComponent(resolveVue('components/ShrimpTable.vue'))
+const FieldRelativeTime = defineAsyncComponent(resolveVue('components/fields/FieldRelativeTime.vue'))
 </script>
 
 <style scoped>