Add local preference signal scaffolding

lib/features/local/local_models.dart

@@ -6,6 +6,10 @@ enum IdeaType { gift, event }
 
 enum ReminderCadence { daily, weekly, monthly }
 
+enum PreferenceSignalPolarity { like, dislike, neutral }
+
+enum PreferenceSignalStatus { inferred, confirmed, dismissed }
+
 @immutable
 class PersonProfile {
   const PersonProfile({
@@ -596,6 +600,137 @@ class SharedInboxEntry {
   }
 }
 
+@immutable
+class PersonPreferenceSignal {
+  const PersonPreferenceSignal({
+    required this.id,
+    required this.personId,
+    required this.key,
+    required this.label,
+    required this.category,
+    required this.polarity,
+    required this.confidence,
+    required this.status,
+    required this.firstSeenAt,
+    required this.lastSeenAt,
+    required this.occurrenceCount,
+    this.sourceApps = const <String>[],
+    this.evidenceMessageIds = const <String>[],
+    this.evidenceSnippets = const <String>[],
+  });
+
+  final String id;
+  final String personId;
+  final String key;
+  final String label;
+  final String category;
+  final PreferenceSignalPolarity polarity;
+  final double confidence;
+  final PreferenceSignalStatus status;
+  final DateTime firstSeenAt;
+  final DateTime lastSeenAt;
+  final int occurrenceCount;
+  final List<String> sourceApps;
+  final List<String> evidenceMessageIds;
+  final List<String> evidenceSnippets;
+
+  PersonPreferenceSignal copyWith({
+    String? id,
+    String? personId,
+    String? key,
+    String? label,
+    String? category,
+    PreferenceSignalPolarity? polarity,
+    double? confidence,
+    PreferenceSignalStatus? status,
+    DateTime? firstSeenAt,
+    DateTime? lastSeenAt,
+    int? occurrenceCount,
+    List<String>? sourceApps,
+    List<String>? evidenceMessageIds,
+    List<String>? evidenceSnippets,
+  }) {
+    return PersonPreferenceSignal(
+      id: id ?? this.id,
+      personId: personId ?? this.personId,
+      key: key ?? this.key,
+      label: label ?? this.label,
+      category: category ?? this.category,
+      polarity: polarity ?? this.polarity,
+      confidence: confidence ?? this.confidence,
+      status: status ?? this.status,
+      firstSeenAt: firstSeenAt ?? this.firstSeenAt,
+      lastSeenAt: lastSeenAt ?? this.lastSeenAt,
+      occurrenceCount: occurrenceCount ?? this.occurrenceCount,
+      sourceApps: sourceApps ?? this.sourceApps,
+      evidenceMessageIds: evidenceMessageIds ?? this.evidenceMessageIds,
+      evidenceSnippets: evidenceSnippets ?? this.evidenceSnippets,
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    return <String, dynamic>{
+      'id': id,
+      'personId': personId,
+      'key': key,
+      'label': label,
+      'category': category,
+      'polarity': polarity.name,
+      'confidence': confidence,
+      'status': status.name,
+      'firstSeenAt': firstSeenAt.toUtc().toIso8601String(),
+      'lastSeenAt': lastSeenAt.toUtc().toIso8601String(),
+      'occurrenceCount': occurrenceCount,
+      'sourceApps': sourceApps,
+      'evidenceMessageIds': evidenceMessageIds,
+      'evidenceSnippets': evidenceSnippets,
+    };
+  }
+
+  factory PersonPreferenceSignal.fromJson(Map<String, dynamic> json) {
+    final String polarityName =
+        json['polarity'] as String? ?? PreferenceSignalPolarity.neutral.name;
+    final String statusName =
+        json['status'] as String? ?? PreferenceSignalStatus.inferred.name;
+    return PersonPreferenceSignal(
+      id: json['id'] as String,
+      personId: json['personId'] as String,
+      key: json['key'] as String,
+      label: json['label'] as String? ?? '',
+      category: json['category'] as String? ?? 'general',
+      polarity: PreferenceSignalPolarity.values.firstWhere(
+        (PreferenceSignalPolarity item) => item.name == polarityName,
+        orElse: () => PreferenceSignalPolarity.neutral,
+      ),
+      confidence: (json['confidence'] as num?)?.toDouble() ?? 0,
+      status: PreferenceSignalStatus.values.firstWhere(
+        (PreferenceSignalStatus item) => item.name == statusName,
+        orElse: () => PreferenceSignalStatus.inferred,
+      ),
+      firstSeenAt: DateTime.parse(
+        json['firstSeenAt'] as String? ??
+            DateTime.now().toUtc().toIso8601String(),
+      ).toLocal(),
+      lastSeenAt: DateTime.parse(
+        json['lastSeenAt'] as String? ??
+            DateTime.now().toUtc().toIso8601String(),
+      ).toLocal(),
+      occurrenceCount: (json['occurrenceCount'] as num?)?.toInt() ?? 1,
+      sourceApps: (json['sourceApps'] as List<dynamic>? ?? <dynamic>[])
+          .map((dynamic item) => '$item')
+          .toList(growable: false),
+      evidenceMessageIds:
+          (json['evidenceMessageIds'] as List<dynamic>? ?? <dynamic>[])
+              .map((dynamic item) => '$item')
+              .toList(growable: false),
+      evidenceSnippets:
+          (json['evidenceSnippets'] as List<dynamic>? ?? <dynamic>[])
+              .map((dynamic item) => '$item')
+              .toList(growable: false),
+    );
+  }
+}
+
 @immutable
 class DashboardSummary {
   const DashboardSummary({
@@ -622,6 +757,7 @@ class LocalDataState {
     this.sourceLinks = const <SourceProfileLink>[],
     this.sharedMessages = const <SharedMessageEntry>[],
     this.sharedInbox = const <SharedInboxEntry>[],
+    this.preferenceSignals = const <PersonPreferenceSignal>[],
   });
 
   final List<PersonProfile> people;
@@ -632,6 +768,7 @@ class LocalDataState {
   final List<SourceProfileLink> sourceLinks;
   final List<SharedMessageEntry> sharedMessages;
   final List<SharedInboxEntry> sharedInbox;
+  final List<PersonPreferenceSignal> preferenceSignals;
 
   LocalDataState copyWith({
     List<PersonProfile>? people,
@@ -642,6 +779,7 @@ class LocalDataState {
     List<SourceProfileLink>? sourceLinks,
     List<SharedMessageEntry>? sharedMessages,
     List<SharedInboxEntry>? sharedInbox,
+    List<PersonPreferenceSignal>? preferenceSignals,
   }) {
     return LocalDataState(
       people: people ?? this.people,
@@ -652,6 +790,7 @@ class LocalDataState {
       sourceLinks: sourceLinks ?? this.sourceLinks,
       sharedMessages: sharedMessages ?? this.sharedMessages,
       sharedInbox: sharedInbox ?? this.sharedInbox,
+      preferenceSignals: preferenceSignals ?? this.preferenceSignals,
     );
   }
 
@@ -697,6 +836,9 @@ class LocalDataState {
       'sharedInbox': sharedInbox
           .map((SharedInboxEntry entry) => entry.toJson())
           .toList(growable: false),
+      'preferenceSignals': preferenceSignals
+          .map((PersonPreferenceSignal signal) => signal.toJson())
+          .toList(growable: false),
     };
   }
 
@@ -750,6 +892,14 @@ class LocalDataState {
                 SharedInboxEntry.fromJson(entry as Map<String, dynamic>),
           )
           .toList(growable: false),
+      preferenceSignals:
+          (json['preferenceSignals'] as List<dynamic>? ?? <dynamic>[])
+              .map(
+                (dynamic signal) => PersonPreferenceSignal.fromJson(
+                  signal as Map<String, dynamic>,
+                ),
+              )
+              .toList(growable: false),
     );
   }