feat: implement ble tag scanning

lib/data/repositories/phoenix_tag_repository.dart

@@ -14,24 +14,72 @@ class PhoenixTagRepository implements TagRepository {
   final RealtimeDataClient realtime;
 
   @override
-  Future<List<Tag>> getTags() => throw UnimplementedError();
+  Future<List<Tag>> getTags() async {
+    final list = await tagClient.getTags();
+    return list.map((j) => Tag.fromJson(j as Map<String, dynamic>)).toList();
+  }
 
   @override
-  Future<Tag> getTag(String id) => throw UnimplementedError();
+  Future<Tag> getTag(int id) async =>
+      Tag.fromJson(await tagClient.getTag(id));
 
   @override
-  Future<Tag> createTag({required String id, required String name}) =>
-      throw UnimplementedError();
+  Future<Tag> createTag({required String tag_id, required String name}) async =>
+      Tag.fromJson(await tagClient.createTag({'tag_id': tag_id, 'name': name}));
 
   @override
-  Future<Tag> updateTag(String id, {String? name}) => throw UnimplementedError();
+  Future<Tag> updateTag(int id, {String? name}) async {
+    final params = <String, dynamic>{};
+    if (name != null) params['name'] = name;
+    return Tag.fromJson(await tagClient.updateTag(id, params));
+  }
 
   @override
-  Future<void> deleteTag(String id) => throw UnimplementedError();
+  Future<void> deleteTag(int id) => tagClient.deleteTag(id);
 
   @override
-  Stream<List<TagPosition>> watchPositions() => throw UnimplementedError();
+  Stream<List<TagPosition>> watchPositions() =>
+      realtime.channel('tags').map((payload) {
+        final list = payload['positions'] as List<dynamic>? ?? [];
+        return list.map((j) {
+          final m = j as Map<String, dynamic>;
+          return TagPosition(
+            tagId: m['tag_id'] as String,
+            name: m['name'] as String,
+            color: m['color'] as String,
+            roomId: m['room_id'] as int?,
+          );
+        }).toList();
+      });
 
   @override
-  Stream<List<Particle>> watchParticleCloud() => throw UnimplementedError();
+  Stream<List<Particle>> watchParticleCloud() =>
+      realtime.channel('localiserd').map((payload) {
+        final list = payload['particles'] as List<dynamic>? ?? [];
+        return list
+            .map((j) => Particle.fromJson(j as Map<String, dynamic>))
+            .toList();
+      });
+
+  @override
+  Stream<Map<int, List<String>>> watchRoomOccupancy() async* {
+    final state = <int, List<String>>{};
+
+    // Seed from the HTTP snapshot so the UI isn't blank until the first push.
+    final snapshot = await tagClient.getOccupancy();
+    for (final entry in snapshot.cast<Map<String, dynamic>>()) {
+      final roomId = entry['room_id'] as int?;
+      if (roomId != null) {
+        state.putIfAbsent(roomId, () => []).add(entry['tag_id'] as String);
+      }
+    }
+    yield Map<int, List<String>>.from(state);
+
+    await for (final payload in realtime.channel('rooms:occupancy')) {
+      final roomId = payload['room_id'] as int;
+      final occupants = (payload['occupants'] as List<dynamic>).cast<String>();
+      state[roomId] = occupants;
+      yield Map<int, List<String>>.from(state);
+    }
+  }
 }

lib/data/repositories/tag_repository.dart

@@ -3,14 +3,18 @@ import '../../domain/models/particle.dart';
 
 abstract class TagRepository {
   Future<List<Tag>> getTags();
-  Future<Tag> getTag(String id);
-  Future<Tag> createTag({required String id, required String name});
-  Future<Tag> updateTag(String id, {String? name});
-  Future<void> deleteTag(String id);
+  Future<Tag> getTag(int id);
+  Future<Tag> createTag({required String tag_id, required String name});
+  Future<Tag> updateTag(int id, {String? name});
+  Future<void> deleteTag(int id);
 
   /// Live stream of all tag positions, pushed by localiserd over Phoenix channel.
   Stream<List<TagPosition>> watchPositions();
 
   /// Live stream of particle filter cloud snapshots.
   Stream<List<Particle>> watchParticleCloud();
+
+  /// Room occupancy delta stream.
+  /// room_id -> list of tag_id strings currently in that room.
+  Stream<Map<int, List<String>>> watchRoomOccupancy();
 }