fix(operation-trace): repair export URL, drop dead action, prune unused keys

- Export download failed because the URL builder appended the path to a
  "/" base, producing a protocol-relative "//api/..." URL that the browser
  read as host "api"; the request never reached the backend. Resolve the
  base to the current origin, mirroring the other URL builders.
- Remove the orphan ``clear_prune`` action: the branch has no prune/clear
  route and no route rule maps to it, so it could never be produced. Its
  i18n key is removed too.
- Remove ``tamperedCount``, now unreferenced after the verification badge
  was split into integrity/chain counters. The operationTrace catalogue is
  now free of unproduced keys.
- Correct the settings controller docstring: only governance, operation
  logs, filters and export routes exist; there is no on-demand delete.

Verified: no producer for clear_prune, classify() can no longer emit it,
operationTrace orphan scan returns none, tsc/check-i18n/prettier/py_compile
all pass.

src/langbot/pkg/api/http/controller/groups/settings.py

@@ -2,12 +2,15 @@
 
 Exposes the "成员操作日志溯源" (member operation traceability) surface:
 
-* ``GET  /api/v1/settings/governance``            read level + template table
-* ``PUT  /api/v1/settings/governance``            change level / retention
-* ``GET  /api/v1/settings/operation-logs``        page through records
-* ``GET  /api/v1/settings/operation-logs/filters`` available filter values
-* ``POST /api/v1/settings/operation-logs/prune``  enforce retention now
-* ``DEL  /api/v1/settings/operation-logs``        clear records
+* ``GET /api/v1/settings/governance``              read level + template table
+* ``PUT /api/v1/settings/governance``              change level / retention
+* ``GET /api/v1/settings/operation-logs``          page through records
+* ``GET /api/v1/settings/operation-logs/filters``  available filter values
+* ``GET /api/v1/settings/operation-logs/export``   download the filtered CSV
+
+Operation records are append-only and there is no route to delete them on
+demand: retention is the only deletion path, and it runs automatically when
+the governance settings change and from the maintenance loop.
 
 Every route requires ``audit.view``, which is granted to the Workspace owner
 and admin only. Write routes additionally require an owning/admin role so a

src/langbot/pkg/api/http/service/settings.py

@@ -212,12 +212,6 @@ ACTION_RULE_TABLE: typing.Final[tuple[ActionRule, ...]] = (
         bucket='audit',
         resource_type='operation_log',
     ),
-    ActionRule(
-        action='clear_prune',
-        category='audit',
-        bucket='write',
-        resource_type='operation_log',
-    ),
     ActionRule(
         action='settings_update',
         category='settings',

web/src/app/infra/http/BackendClient.ts

@@ -1867,12 +1867,19 @@ export class BackendClient extends BaseHttpClient {
       params.set(key, String(value));
     }
     const suffix = params.toString();
-    return `${this.getBaseUrl()}/api/v1/settings/operation-logs/export${
+    // A base of "/" means "same origin". Appending the path directly produced
+    // a protocol-relative "//api/..." URL, which a browser reads as the host
+    // "api" — the export request then never reached the backend. Resolve the
+    // base to the current origin first, mirroring the other URL builders here.
+    const apiBase =
+      this.instance.defaults.baseURL === '/' || !this.instance.defaults.baseURL
+        ? window.location.origin
+        : this.instance.defaults.baseURL.replace(/\/$/, '');
+    return `${apiBase}/api/v1/settings/operation-logs/export${
       suffix ? `?${suffix}` : ''
     }`;
   }
 
-
   public setPassword(
     newPassword: string,
     currentPassword?: string,

web/src/i18n/locales/en-US.ts

@@ -2752,7 +2752,6 @@ const enUS = {
     redacted: 'Redacted',
     tamperedBadge: 'Possibly tampered',
     verifiedBadge: 'Verified',
-    tamperedCount: '{{count}} records failed verification',
     integrityFailedCount: '{{count}} hash mismatches',
     chainFailedCount: '{{count}} broken links',
     levels: {
@@ -2778,7 +2777,6 @@ const enUS = {
     },
     actions: {
       audit_log_view: 'View operation logs',
-      clear_prune: 'Prune records by policy',
       settings_update: 'Update tracing settings',
       settings_view: 'View tracing settings',
       member_invite: 'Invite member',

web/src/i18n/locales/es-ES.ts

@@ -2807,7 +2807,6 @@ const esES = {
     redacted: 'Oculto',
     tamperedBadge: 'Posible manipulación',
     verifiedBadge: 'Verificado',
-    tamperedCount: '{{count}} registros fallaron la verificación',
     integrityFailedCount: '{{count}} hashes no coinciden',
     chainFailedCount: '{{count}} enlaces rotos',
     levels: {
@@ -2833,7 +2832,6 @@ const esES = {
     },
     actions: {
       audit_log_view: 'Ver registros de operación',
-      clear_prune: 'Depurar registros según la política',
       settings_update: 'Actualizar ajustes de trazabilidad',
       settings_view: 'Ver ajustes de trazabilidad',
       member_invite: 'Invitar miembro',

web/src/i18n/locales/ja-JP.ts

@@ -2770,7 +2770,6 @@ const jaJP = {
     redacted: 'マスク済み',
     tamperedBadge: '改ざんの可能性',
     verifiedBadge: '検証済み',
-    tamperedCount: '{{count}} 件が検証に失敗',
     integrityFailedCount: '{{count}} 件のハッシュ不一致',
     chainFailedCount: '{{count}} 件のリンク断絶',
     levels: {
@@ -2796,7 +2795,6 @@ const jaJP = {
     },
     actions: {
       audit_log_view: '操作ログを閲覧',
-      clear_prune: 'ポリシーで記録を整理',
       settings_update: 'トレーサビリティ設定を変更',
       settings_view: 'トレーサビリティ設定を閲覧',
       member_invite: 'メンバーを招待',

web/src/i18n/locales/ru-RU.ts

@@ -2777,7 +2777,6 @@ const ruRU = {
     redacted: 'Скрыто',
     tamperedBadge: 'Возможна подмена',
     verifiedBadge: 'Проверено',
-    tamperedCount: 'Записей с ошибкой проверки: {{count}}',
     integrityFailedCount: 'Несовпадение хэша: {{count}}',
     chainFailedCount: 'Разрыв связи: {{count}}',
     levels: {
@@ -2803,7 +2802,6 @@ const ruRU = {
     },
     actions: {
       audit_log_view: 'Просмотр журнала операций',
-      clear_prune: 'Очистка записей по политике',
       settings_update: 'Изменение настроек трассировки',
       settings_view: 'Просмотр настроек трассировки',
       member_invite: 'Приглашение участника',

web/src/i18n/locales/th-TH.ts

@@ -2704,7 +2704,6 @@ const thTH = {
     redacted: 'ปิดบังแล้ว',
     tamperedBadge: 'อาจถูกแก้ไข',
     verifiedBadge: 'ตรวจสอบผ่าน',
-    tamperedCount: 'มี {{count}} บันทึกที่ตรวจสอบไม่ผ่าน',
     integrityFailedCount: 'แฮชไม่ตรงกัน {{count}} รายการ',
     chainFailedCount: 'ลิงก์ขาด {{count}} รายการ',
     levels: {
@@ -2730,7 +2729,6 @@ const thTH = {
     },
     actions: {
       audit_log_view: 'ดูบันทึกการดำเนินการ',
-      clear_prune: 'ล้างบันทึกตามนโยบาย',
       settings_update: 'แก้ไขการตั้งค่าการติดตาม',
       settings_view: 'ดูการตั้งค่าการติดตาม',
       member_invite: 'เชิญสมาชิก',

web/src/i18n/locales/vi-VN.ts

@@ -2739,7 +2739,6 @@ const viVN = {
     redacted: 'Đã ẩn',
     tamperedBadge: 'Có thể bị sửa',
     verifiedBadge: 'Đã xác minh',
-    tamperedCount: '{{count}} bản ghi không vượt qua kiểm tra',
     integrityFailedCount: '{{count}} mã băm không khớp',
     chainFailedCount: '{{count}} liên kết bị đứt',
     levels: {
@@ -2765,7 +2764,6 @@ const viVN = {
     },
     actions: {
       audit_log_view: 'Xem nhật ký thao tác',
-      clear_prune: 'Dọn bản ghi theo chính sách',
       settings_update: 'Cập nhật cài đặt truy vết',
       settings_view: 'Xem cài đặt truy vết',
       member_invite: 'Mời thành viên',

web/src/i18n/locales/zh-Hans.ts

@@ -2601,7 +2601,6 @@ const zhHans = {
     redacted: '已脱敏',
     tamperedBadge: '可能被篡改',
     verifiedBadge: '校验通过',
-    tamperedCount: '{{count}} 条记录校验异常',
     integrityFailedCount: '{{count}} 条哈希不匹配',
     chainFailedCount: '{{count}} 条链路断裂',
     levels: {
@@ -2627,7 +2626,6 @@ const zhHans = {
     },
     actions: {
       audit_log_view: '查看操作日志',
-      clear_prune: '按策略清理记录',
       settings_update: '修改溯源设置',
       settings_view: '查看溯源设置',
       member_invite: '邀请成员',

web/src/i18n/locales/zh-Hant.ts

@@ -2602,7 +2602,6 @@ const zhHant = {
     redacted: '已遮罩',
     tamperedBadge: '可能被竄改',
     verifiedBadge: '驗證通過',
-    tamperedCount: '{{count}} 筆記錄驗證異常',
     integrityFailedCount: '{{count}} 筆雜湊不符',
     chainFailedCount: '{{count}} 筆鏈結中斷',
     levels: {
@@ -2628,7 +2627,6 @@ const zhHant = {
     },
     actions: {
       audit_log_view: '查看操作日誌',
-      clear_prune: '依策略清理記錄',
       settings_update: '修改溯源設定',
       settings_view: '查看溯源設定',
       member_invite: '邀請成員',