feat(course): reset student course progress (#671)

* feat(course): add reset student course progress action

Give course admins and tutors a destructive reset-progress flow on the
student people detail page. The backend clears learner progress for one
(courseId, memberId) pair in a single transaction while keeping the
groupmember enrolled, and logs an audit summary. The dashboard shows a
confirmation dialog with impact counts from analytics before deleting.

Co-authored-by: Rotimi Best <[email protected]>

* fix(i18n): add localized reset progress strings for all locales

Co-authored-by: Rotimi Best <[email protected]>

* fix(course): scope reset progress to course data only

Stop deleting org-level community questions and answers during course
progress reset. Fix course newsfeed deletion order so comments on a
student's posts are removed before the posts themselves. Restrict reset
to student members, move analytics loading to the person detail layout,
and rename impact copy to course newsfeed only.

Co-authored-by: Rotimi Best <[email protected]>

* fix(course): address Greptile review on reset progress

Make progressImpact opt-in via includeProgressImpact query param so
analytics requests avoid extra DB work unless the reset dialog needs it.
Count only student-authored course newsfeed posts and comments in the
impact summary to avoid double-counting replies on the student's posts.

Co-authored-by: Rotimi Best <[email protected]>

---------

Co-authored-by: Cursor Agent <[email protected]>
Co-authored-by: Rotimi Best <[email protected]>

apps/dashboard/src/lib/utils/translations/de.json

@@ -242,6 +242,10 @@
         "unpinned": "Nicht angepinnt",
         "successfully": "Erfolgreich",
         "feed_delete_success": "Feed erfolgreich gelöscht"
+      },
+      "people": {
+        "progress_reset": "Fortschritt zurückgesetzt",
+        "progress_reset_failed": "Fortschritt konnte nicht zurückgesetzt werden"
       }
     },
     "landing_page_settings": {
@@ -1100,6 +1104,26 @@
           "no": "Nein",
           "yes": "Ja"
         },
+        "reset_progress": {
+          "button": "Fortschritt zurücksetzen",
+          "dialog": {
+            "title": "Fortschritt von {studentName} zurücksetzen?",
+            "intro": "Dadurch wird der Fortschritt dieses Teilnehmers in diesem Kurs dauerhaft gelöscht. Die Person bleibt eingeschrieben und kann bei Lektion 1 neu beginnen.",
+            "bullets": {
+              "lessons": "Abgeschlossene Lektionen — {completed} von {total}",
+              "exercises": "Eingereichte Übungen — {count} Abgaben",
+              "comments": "Lektionskommentare dieses Teilnehmers — {count}",
+              "newsfeed": "Kurs-Newsfeed-Beiträge und Antworten dieses Teilnehmers — {count}",
+              "video_progress": "Videofortschritt — {count} verfolgte Lektionen",
+              "attendance": "Anwesenheitseinträge — {count}",
+              "certificate_yes": "Zertifizierungs-/Compliance-Daten — ja",
+              "certificate_no": "Zertifizierungs-/Compliance-Daten — nein"
+            },
+            "warning": "Dies kann nicht rückgängig gemacht werden.",
+            "cancel": "Abbrechen",
+            "confirm": "Löschen"
+          }
+        },
         "invite_modal": {
           "title": "Leute einladen",
           "invite": "Laden Sie Tutoren ein",