feat(app): More info for studysets, paths, notes and PDFs

Wherever the old menus offered it: the studyset's options, a path's
(in the list and in the runner), a note's, and a PDF's, all on the
shared sheet the cards use: when it was made (from its UUID v7 id) and
last changed where that is kept, its ids to copy (parent, studyset,
PDF), and for a PDF its file.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMm7usAo6q9ZZRoPkWjoxi
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

halkyon_learn_flutter/lib/l10n/app_de.arb

@@ -681,6 +681,8 @@
   "moreInfoItemId": "Element-ID",
   "moreInfoStudysetId": "Lernset-ID",
   "moreInfoPdfId": "PDF-Quellen-ID",
+  "moreInfoParentId": "Übergeordnete ID",
+  "moreInfoFile": "Datei",
   "moreInfoReviews": "Wiederholungen",
   "moreInfoReviewCount": "Anzahl Wiederholungen",
   "moreInfoLastReviewed": "Zuletzt wiederholt",