feat(app): More info about a card

"More info", in a card's menu while studying or in the list, shows when
it was made and last changed (its ids say), its id and its studyset's
(and its PDF's), each copied with a tap, and how often it was studied
and when last. The sheet is a shared one, for notes and paths to follow.

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

halkyon_learn_flutter/lib/l10n/app_en.arb

@@ -708,6 +708,17 @@
   "commonSave": "Save",
   "commonClose": "Close",
   "commonUndo": "Undo",
+  "moreInfo": "More info",
+  "moreInfoCreated": "Created",
+  "moreInfoModified": "Last modified",
+  "moreInfoItemId": "Item ID",
+  "moreInfoStudysetId": "Studyset ID",
+  "moreInfoPdfId": "PDF source ID",
+  "moreInfoReviews": "Reviews",
+  "moreInfoReviewCount": "Review count",
+  "moreInfoLastReviewed": "Last reviewed",
+  "moreInfoCopy": "Copy",
+  "copiedToClipboard": "Copied to clipboard",
   "commonTryAgain": "Try again",
   "personDataFailed": "Couldn't open this device's data.",
   "sessionUnreachable": "Couldn't reach the server.",