feat(openai): port /responses/compact account support flow (PR #1555)

将 vansour/sub2api#1555 的 OpenAI compact 能力建模手工移植到当前 main：账号
级 compact 状态/auto-force_on-force_off 模式、compact-only 模型映射、调度器
tier 分层（已支持 > 未知 > 已知不支持）、管理后台 compact 主动探测，以及对应
i18n/状态徽章。普通 /responses 流量行为不变，无数据库迁移。

frontend/src/i18n/locales/en.ts

@@ -2848,6 +2848,22 @@ export default {
         codexCLIOnly: 'Codex official clients only',
         codexCLIOnlyDesc:
           'Only applies to OpenAI OAuth. When enabled, only Codex official client families are allowed; when disabled, the gateway bypasses this restriction and keeps existing behavior.',
+        compactMode: 'Compact mode',
+        compactModeDesc:
+          'Controls how this account participates in /responses/compact routing. Auto follows probe results, Force On always allows, Force Off always excludes.',
+        compactModeAuto: 'Auto',
+        compactModeForceOn: 'Force On',
+        compactModeForceOff: 'Force Off',
+        compactModelMapping: 'Compact-only model mapping',
+        compactModelMappingDesc:
+          'Only applies to /responses/compact. Use this when the upstream compact endpoint requires a special compact model.',
+        compactSupported: 'Compact supported',
+        compactUnsupported: 'Compact unsupported',
+        compactUnknown: 'Compact unknown',
+        compactLastChecked: 'Last compact probe',
+        testMode: 'Test mode',
+        testModeDefault: 'Default request',
+        testModeCompact: 'Compact probe',
         modelRestrictionDisabledByPassthrough: 'Automatic passthrough is enabled: model whitelist/mapping will not take effect.',
       },
       anthropic: {