feat: a dictionary's corrections reach the cards made from it, by offer

Every dictionary entry now has a version: 16 hex digits of the SHA-256 of
what cards take of it (headword, reading, entry), made by the loader and
carried on every hit. A card keeps the version it took (card schema 8).
DictionaryEndpoint.changed returns, of the entries named with the
versions cards keep (1,000 at most a call; the app asks 500 at a time),
those whose version is another now.

The card browser says how many cards are behind their dictionary and takes
the corrections at a tap (decided 2026-10-09: by offer, never by
themselves). Taking one writes the entry as it is now over the revision
in which the card last took it, beside whatever came after, so the
revisions merge per side as two devices' edits do (ADR 0003): a side only
the dictionary changed takes the correction, a side the person changed
too is a conflict settled in the composer, whose words now name that
case. Cards made before versions are never offered one.

The server rereads its dictionary folder hourly now, not daily: the
dictionaries service fills its volume after an instance's first start,
and an hour with nothing changed costs a hash of each file.

Migration 20261009145434785-dictionary-entry-version: adds
dictionary_entry.version, text NOT NULL DEFAULT '' (rows loaded before
have none and are never reported as corrected), and by hand empties
dictionary_source."fileHash", so every source loads once more and its
entries get their versions; the schema stays as definition.sql says. The
old server goes on working until the switch.

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_localizations_en.dart

@@ -1745,6 +1745,9 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get cardDictionaryEntry => 'Dictionary entry';
 
+  @override
+  String get cardDictionaryVersion => 'Dictionary version';
+
   @override
   String get studysetFromDictionary => 'From the dictionary';
 
@@ -1938,6 +1941,47 @@ class AppLocalizationsEn extends AppLocalizations {
     return 'Characters from $sources.';
   }
 
+  @override
+  String dictionaryUpdatesBehind(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other:
+          '$count cards are behind the dictionary: their entries were corrected since they were made.',
+      one: '1 card is behind the dictionary: its entry was corrected since it was made.',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String get dictionaryUpdatesTake => 'Take the corrections';
+
+  @override
+  String dictionaryUpdatesTaken(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count cards updated.',
+      one: '1 card updated.',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String dictionaryUpdatesToSettle(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count have a change of yours there too: open them to choose.',
+      one: 'One has a change of yours there too: open it to choose.',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String get dictionaryUpdatesFailed =>
+      'Couldn\'t take the corrections. Try again.';
+
   @override
   String get kanjiStrokeOrder => 'Stroke order';
 
@@ -2273,7 +2317,7 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get composerConflict =>
-      'This flashcard was changed differently on two devices. Choose the version to keep of each part below.';
+      'This flashcard was changed in two ways at once: on two of your devices, or by you and by a correction from the dictionary. Choose the version to keep of each part below.';
 
   @override
   String get composerKeepThis => 'Keep this';