feat(admin): reset a user's recommendations from the users panel

- POST /admin/users/{id}/reset-recommendations clears the taste profile
  (onboarding, CF vector, bandit), play stats and wave impressions; likes,
  dislikes and history stay, wave sessions stay so a playing wave keeps going
- moderators may reset plain users, admins anyone including themselves;
  the reset is written to the audit log
- users panel gets the menu action with a confirmation; docs updated

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/i18n/locales/en/admin.json

@@ -24,6 +24,9 @@
     "delete_confirm": "Delete {{username}}? Their history and likes will be lost.",
     "block_confirm": "Block {{username}}? All their sessions will end.",
     "reset_confirm": "Reset {{username}}'s password? All their sessions will end.",
+    "reset_recommendations": "Reset recommendations",
+    "recs_confirm": "Reset {{username}}'s recommendations? The wave will start learning their taste from scratch and ask for favourite artists again. Likes and history stay.",
+    "recs_done": "{{username}}'s recommendations were reset",
     "confirm": "Confirm",
     "you": "you"
   },
@@ -60,6 +63,7 @@
       "user.block": "User blocked",
       "user.unblock": "User unblocked",
       "user.password_reset": "Password reset",
+      "user.recommendations_reset": "Recommendations reset",
       "user.delete": "User deleted"
     }
   },