feat(channel): 模型标签输入 + $/MTok 价格单位 + 左开右闭区间 + i18n

- 模型输入改为标签列表（输入回车添加，支持粘贴批量导入）
- 价格显示单位改为 $/MTok（每百万 token），提交时自动转换
- Token 模式增加图片输出价格字段（适配 Gemini 图片模型按 token 计费）
- 区间边界改为左开右闭 (min, max]，右边界包含
- 默认价格作为未命中区间时的回退价格
- 添加完整中英文 i18n 翻译

frontend/src/components/admin/channel/IntervalRow.vue

@@ -1,125 +1,66 @@
 <template>
   <div class="flex items-start gap-2 rounded border border-gray-200 bg-white p-2 dark:border-dark-500 dark:bg-dark-700">
-    <!-- Token mode: context range + prices -->
+    <!-- Token mode: context range + prices ($/MTok) -->
     <template v-if="mode === 'token'">
       <div class="w-20">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.minTokens', 'Min (K)') }}</label>
-        <input
-          :value="interval.min_tokens"
-          @input="emitField('min_tokens', toInt(($event.target as HTMLInputElement).value))"
-          type="number"
-          min="0"
-          class="input mt-0.5 text-xs"
-        />
+        <label class="text-xs text-gray-400">Min</label>
+        <input :value="interval.min_tokens" @input="emitField('min_tokens', toInt(($event.target as HTMLInputElement).value))"
+          type="number" min="0" class="input mt-0.5 text-xs" />
       </div>
       <div class="w-20">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.maxTokens', 'Max (K)') }}</label>
-        <input
-          :value="interval.max_tokens ?? ''"
-          @input="emitField('max_tokens', toIntOrNull(($event.target as HTMLInputElement).value))"
-          type="number"
-          min="0"
-          class="input mt-0.5 text-xs"
-          :placeholder="'∞'"
-        />
+        <label class="text-xs text-gray-400">Max <span class="text-gray-300">(含)</span></label>
+        <input :value="interval.max_tokens ?? ''" @input="emitField('max_tokens', toIntOrNull(($event.target as HTMLInputElement).value))"
+          type="number" min="0" class="input mt-0.5 text-xs" :placeholder="'∞'" />
       </div>
       <div class="flex-1">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.inputPrice', 'Input') }}</label>
-        <input
-          :value="interval.input_price"
-          @input="emitField('input_price', ($event.target as HTMLInputElement).value)"
-          type="number"
-          step="any" min="0"
-          class="input mt-0.5 text-xs"
-        />
+        <label class="text-xs text-gray-400">{{ t('admin.channels.form.inputPrice', '输入') }} <span class="text-gray-300">$/M</span></label>
+        <input :value="interval.input_price" @input="emitField('input_price', ($event.target as HTMLInputElement).value)"
+          type="number" step="any" min="0" class="input mt-0.5 text-xs" />
       </div>
       <div class="flex-1">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.outputPrice', 'Output') }}</label>
-        <input
-          :value="interval.output_price"
-          @input="emitField('output_price', ($event.target as HTMLInputElement).value)"
-          type="number"
-          step="any" min="0"
-          class="input mt-0.5 text-xs"
-        />
+        <label class="text-xs text-gray-400">{{ t('admin.channels.form.outputPrice', '输出') }} <span class="text-gray-300">$/M</span></label>
+        <input :value="interval.output_price" @input="emitField('output_price', ($event.target as HTMLInputElement).value)"
+          type="number" step="any" min="0" class="input mt-0.5 text-xs" />
       </div>
       <div class="flex-1">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.cacheWritePrice', 'Cache W') }}</label>
-        <input
-          :value="interval.cache_write_price"
-          @input="emitField('cache_write_price', ($event.target as HTMLInputElement).value)"
-          type="number"
-          step="any" min="0"
-          class="input mt-0.5 text-xs"
-        />
+        <label class="text-xs text-gray-400">{{ t('admin.channels.form.cacheWritePrice', '缓存W') }} <span class="text-gray-300">$/M</span></label>
+        <input :value="interval.cache_write_price" @input="emitField('cache_write_price', ($event.target as HTMLInputElement).value)"
+          type="number" step="any" min="0" class="input mt-0.5 text-xs" />
       </div>
       <div class="flex-1">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.cacheReadPrice', 'Cache R') }}</label>
-        <input
-          :value="interval.cache_read_price"
-          @input="emitField('cache_read_price', ($event.target as HTMLInputElement).value)"
-          type="number"
-          step="any" min="0"
-          class="input mt-0.5 text-xs"
-        />
+        <label class="text-xs text-gray-400">{{ t('admin.channels.form.cacheReadPrice', '缓存R') }} <span class="text-gray-300">$/M</span></label>
+        <input :value="interval.cache_read_price" @input="emitField('cache_read_price', ($event.target as HTMLInputElement).value)"
+          type="number" step="any" min="0" class="input mt-0.5 text-xs" />
       </div>
     </template>
 
-    <!-- Per-request / Image mode: tier label + price -->
+    <!-- Per-request / Image mode: tier label + context range + price -->
     <template v-else>
       <div class="w-24">
         <label class="text-xs text-gray-400">
-          {{ mode === 'image'
-            ? t('admin.channels.form.resolution', 'Resolution')
-            : t('admin.channels.form.tierLabel', 'Tier')
-          }}
+          {{ mode === 'image' ? t('admin.channels.form.resolution', '分辨率') : t('admin.channels.form.tierLabel', '层级') }}
         </label>
-        <input
-          :value="interval.tier_label"
-          @input="emitField('tier_label', ($event.target as HTMLInputElement).value)"
-          type="text"
-          class="input mt-0.5 text-xs"
-          :placeholder="mode === 'image' ? '1K / 2K / 4K' : ''"
-        />
+        <input :value="interval.tier_label" @input="emitField('tier_label', ($event.target as HTMLInputElement).value)"
+          type="text" class="input mt-0.5 text-xs" :placeholder="mode === 'image' ? '1K / 2K / 4K' : ''" />
       </div>
       <div class="w-20">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.minTokens', 'Min') }}</label>
-        <input
-          :value="interval.min_tokens"
-          @input="emitField('min_tokens', toInt(($event.target as HTMLInputElement).value))"
-          type="number"
-          min="0"
-          class="input mt-0.5 text-xs"
-        />
+        <label class="text-xs text-gray-400">Min</label>
+        <input :value="interval.min_tokens" @input="emitField('min_tokens', toInt(($event.target as HTMLInputElement).value))"
+          type="number" min="0" class="input mt-0.5 text-xs" />
       </div>
       <div class="w-20">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.maxTokens', 'Max') }}</label>
-        <input
-          :value="interval.max_tokens ?? ''"
-          @input="emitField('max_tokens', toIntOrNull(($event.target as HTMLInputElement).value))"
-          type="number"
-          min="0"
-          class="input mt-0.5 text-xs"
-          :placeholder="'∞'"
-        />
+        <label class="text-xs text-gray-400">Max <span class="text-gray-300">(含)</span></label>
+        <input :value="interval.max_tokens ?? ''" @input="emitField('max_tokens', toIntOrNull(($event.target as HTMLInputElement).value))"
+          type="number" min="0" class="input mt-0.5 text-xs" :placeholder="'∞'" />
       </div>
       <div class="flex-1">
-        <label class="text-xs text-gray-400">{{ t('admin.channels.form.perRequestPrice', 'Price') }}</label>
-        <input
-          :value="interval.per_request_price"
-          @input="emitField('per_request_price', ($event.target as HTMLInputElement).value)"
-          type="number"
-          step="any" min="0"
-          class="input mt-0.5 text-xs"
-        />
+        <label class="text-xs text-gray-400">{{ t('admin.channels.form.perRequestPrice', '单次价格') }} <span class="text-gray-300">$</span></label>
+        <input :value="interval.per_request_price" @input="emitField('per_request_price', ($event.target as HTMLInputElement).value)"
+          type="number" step="any" min="0" class="input mt-0.5 text-xs" />
       </div>
     </template>
 
-    <button
-      type="button"
-      @click="emit('remove')"
-      class="mt-4 rounded p-0.5 text-gray-400 hover:text-red-500"
-    >
+    <button type="button" @click="emit('remove')" class="mt-4 rounded p-0.5 text-gray-400 hover:text-red-500">
       <Icon name="x" size="sm" />
     </button>
   </div>