feat(dashboard): add content page options menu (#757)

* feat(dashboard): add content page options menu

Add a three-dot menu on the course Content page with actions to unlock
all locked lessons/exercises and toggle content grouping. Reuse shared
locked-content collection logic from course settings.

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

* fix(dashboard): keep unlock-all enabled and add menu icons

Show a success snackbar when all content is already unlocked instead of
disabling the action. Add lock-open and table-of-contents icons to menu items.

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

* fix(dashboard): check courseApi.update return for grouping toggle

Use the update() return value instead of courseApi.success, which can be
false after a successful PUT if the follow-up refresh request fails.

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

---------

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

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

@@ -2236,6 +2236,12 @@
         },
         "add_content_section_title_placeholder": "e.g., Module 1: Introduction",
         "add_content_lesson_title_placeholder": "e.g., Getting Started with Variables",
+        "content_menu": {
+          "label": "Content options",
+          "unlock_all": "Unlock all content",
+          "enable_grouping": "Enable content grouping",
+          "disable_grouping": "Disable content grouping"
+        },
         "join_lesson": "Join lesson",
         "no_link": "No link",
         "no_tutor": "No tutor added",
@@ -4173,6 +4179,9 @@
     "course_settings": {
       "success": {
         "unlocked_all_content": "All course items unlocked",
+        "all_content_already_unlocked": "All content is already unlocked",
+        "content_grouping_enabled": "Content grouping enabled",
+        "content_grouping_disabled": "Content grouping disabled",
         "download": "Download Complete",
         "saved": "Saved successfully",
         "successful_integration": "Integration successful",