feat: GeoIP-based geo detection + configurable rename template

- Add MaxMind GeoLite2-City mmdb auto-download and IP-based geo lookup
  (covers all 249 countries globally, replacing limited 8-country regex)
- Add RenameOptions with 5 toggleable fields (flag/alias/country/city/index)
  stored as rename_options_json on collections
- Collection rename pipeline uses DetectGeoWithServer(name, server) which
  tries GeoIP lookup first, falls back to name-based regex matching
- Chinese country/city names + emoji flag prefix
- Country-city dedup: skip city when it equals country (e.g. 香港/香港)
- URI fragment encoding: url.QueryEscape -> url.PathEscape (%20 not +)
- Egress cache key excludes name field so renamed nodes still match cache
- Frontend: 5 toggle buttons in collection edit form, default all on
- Migrations: 0004 (source alias + collection rename_enabled),
  0005 (collection rename_options_json)

frontend/src/pages/Collections.vue

@@ -20,7 +20,7 @@
               <span>原始节点: {{ nodeCounts[col.id]?.original ?? '-' }}</span>
               <span>处理后: {{ nodeCounts[col.id]?.processed ?? '-' }}</span>
               <span>订阅源: {{ col.sourceIds?.length || 0 }}</span>
-              <span>过滤器: {{ col.filters?.length || 0 }}</span>
+              <span v-if="col.renameEnabled" class="text-purple-500">重命名已开启</span>
               <span>模板: {{ col.templateId || 'default' }}</span>
               <span v-if="col.ignoreFailed">忽略失败</span>
             </div>
@@ -114,18 +114,23 @@
           <label class="flex items-center gap-2 text-sm">
             <input type="checkbox" v-model="form.ignoreFailed" class="rounded" /> 忽略失败源
           </label>
+          <label class="flex items-center gap-2 text-sm">
+            <input type="checkbox" v-model="form.renameEnabled" class="rounded" /> 节点重命名
+          </label>
         </div>
-        <div>
-          <div class="flex items-center justify-between mb-1">
-            <label class="text-sm font-medium">过滤器</label>
-            <button class="text-xs text-primary-600 hover:underline" @click="form.filters.push({ type: 'include', pattern: '' })">+ 添加</button>
-          </div>
-          <div v-for="(f, i) in form.filters" :key="i" class="flex gap-1 mb-1.5">
-            <select v-model="f.type" class="px-2 py-1 border rounded text-xs w-28">
-              <option v-for="t in filterTypes" :key="t" :value="t">{{ t }}</option>
-            </select>
-            <input v-model="f.pattern" placeholder="pattern" class="flex-1 px-2 py-1 border rounded text-xs" />
-            <button class="px-2 py-1 text-xs text-red-500 hover:bg-red-50 rounded" @click="form.filters.splice(i,1)">×</button>
+        <div v-if="form.renameEnabled" class="rounded-lg bg-blue-50 px-3 py-2 text-xs text-blue-600">
+          开启后，所有节点将按以下格式重命名：<br>
+          <code class="text-blue-800">[国旗] [别名] [国家] [城市] [序号]</code><br>
+          点击下方按钮可切换各字段的显示（默认全开）：
+          <div class="flex flex-wrap gap-1.5 mt-2">
+            <button type="button" v-for="opt in renameOptionList" :key="opt.key"
+              class="px-2.5 py-1 rounded-full text-xs font-medium border transition-colors"
+              :class="form.renameOptions[opt.key]
+                ? 'bg-blue-600 text-white border-blue-600'
+                : 'bg-white text-gray-500 border-gray-300 hover:border-gray-400'"
+              @click="form.renameOptions[opt.key] = !form.renameOptions[opt.key]">
+              {{ opt.label }}
+            </button>
           </div>
         </div>
       </div>
@@ -169,8 +174,18 @@ const confirmDialog = ref({ show: false, title: '', message: '', danger: false,
 
 const filterTypes = ['include', 'exclude', 'rename', 'dedupe', 'sort', 'delete-field', 'flag', 'quick', 'resolve', 'custom']
 
+const renameOptionList = [
+  { key: 'flag',    label: '国旗' },
+  { key: 'alias',   label: '别名' },
+  { key: 'country', label: '国家' },
+  { key: 'city',    label: '城市' },
+  { key: 'index',   label: '序号' },
+]
+
+const defaultRenameOptions = () => ({ flag: true, alias: true, country: true, city: true, index: true })
+
 const emptyForm = () => ({
-  name: '', sourceIds: [], filters: [], templateId: '', ignoreFailed: true, enabled: true
+  name: '', sourceIds: [], renameEnabled: false, renameOptions: defaultRenameOptions(), templateId: '', ignoreFailed: true, enabled: true
 })
 const form = reactive(emptyForm())
 
@@ -217,10 +232,18 @@ function openCreate() {
 }
 
 function editCol(col) {
+  const ro = col.renameOptions || {}
   Object.assign(form, {
     name: col.id,
     sourceIds: [...(col.sourceIds || [])],
-    filters: JSON.parse(JSON.stringify(col.filters || [])),
+    renameEnabled: col.renameEnabled === true,
+    renameOptions: {
+      flag:    ro.flag !== false,
+      alias:   ro.alias !== false,
+      country: ro.country !== false,
+      city:    ro.city !== false,
+      index:   ro.index !== false,
+    },
     templateId: col.templateId || '',
     ignoreFailed: col.ignoreFailed !== false,
     enabled: col.enabled !== false,

frontend/src/pages/Sources.vue

@@ -14,6 +14,7 @@
           <div class="flex-1 min-w-0">
             <div class="flex items-center gap-2">
               <span class="font-medium text-gray-900">{{ src.name }}</span>
+              <span v-if="src.alias" class="px-1.5 py-0.5 rounded text-xs bg-purple-100 text-purple-700">{{ src.alias }}</span>
               <span class="px-1.5 py-0.5 rounded text-xs"
                 :class="src.type === 'remote' ? 'bg-blue-100 text-blue-700' : 'bg-gray-100 text-gray-600'">{{ src.type }}</span>
               <span v-if="!src.enabled" class="px-1.5 py-0.5 rounded text-xs bg-red-100 text-red-700">已禁用</span>
@@ -22,6 +23,7 @@
             <div class="flex gap-2 mt-1 text-xs text-gray-400">
               <span>原始节点: {{ nodeCounts[src.id]?.original ?? '-' }}</span>
               <span>处理后: {{ nodeCounts[src.id]?.processed ?? '-' }}</span>
+              <span v-if="src.alias">别名: {{ src.alias }}</span>
               <span>过滤器: {{ src.filters?.length || 0 }}</span>
               <span v-if="src.createdAt">创建: {{ formatTime(src.createdAt) }}</span>
             </div>
@@ -87,11 +89,19 @@
     <!-- Create/Edit Modal -->
     <Modal v-model="showModal" :title="editing ? '编辑订阅源' : '新建订阅源'">
       <div class="space-y-4">
-        <div>
-          <label class="block text-sm font-medium mb-1">名称 / ID</label>
-          <input v-model="form.name" :disabled="editing" placeholder="my-sub"
-            class="w-full px-3 py-2 border rounded-lg text-sm disabled:bg-gray-100" />
-          <p class="text-xs text-gray-400 mt-0.5">仅支持小写字母、数字、下划线、连字符</p>
+        <div class="grid grid-cols-2 gap-3">
+          <div>
+            <label class="block text-sm font-medium mb-1">名称 / ID</label>
+            <input v-model="form.name" :disabled="editing" placeholder="my-sub"
+              class="w-full px-3 py-2 border rounded-lg text-sm disabled:bg-gray-100" />
+            <p class="text-xs text-gray-400 mt-0.5">小写字母、数字、下划线、连字符</p>
+          </div>
+          <div>
+            <label class="block text-sm font-medium mb-1">别名 (Alias)</label>
+            <input v-model="form.alias" placeholder="如：机场A"
+              class="w-full px-3 py-2 border rounded-lg text-sm" />
+            <p class="text-xs text-gray-400 mt-0.5">合集重命名时作为节点标识</p>
+          </div>
         </div>
         <div>
           <label class="block text-sm font-medium mb-1">类型</label>
@@ -225,7 +235,7 @@ const filterGuides = [
 ]
 
 const emptyForm = () => ({
-  name: '', type: 'remote', url: '', content: '', enabled: true, filters: []
+  name: '', alias: '', type: 'remote', url: '', content: '', enabled: true, filters: []
 })
 const form = reactive(emptyForm())
 
@@ -305,6 +315,7 @@ function sourcePreviewPayload(src) {
   return {
     id: src.id,
     name: src.name,
+    alias: src.alias,
     type: src.type,
     url: src.url,
     content: src.content,
@@ -321,6 +332,7 @@ function openCreate() {
 function editSource(src) {
   Object.assign(form, {
     name: src.id,
+    alias: src.alias || '',
     type: src.type || 'remote',
     url: src.url || '',
     content: src.content || '',
@@ -339,6 +351,7 @@ async function save() {
   try {
     const payload = {
       name: form.name,
+      alias: form.alias,
       type: form.type,
       url: form.url,
       content: form.content,