Use correct sensor precision in sensors widget (#3269)

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## Summary
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importantly what they aim to achieve -->
Pending on: #3268

CC: @Penait1 

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## Link to pull request in Documentation repository
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corresponding pull request in the Companion App Documentation repository
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Documentation: home-assistant/companion.home-assistant#

## Any other notes
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Sources/Extensions/AppIntents/Widget/Sensor/WidgetSensorsAppIntentTimelineProvider.swift

@@ -123,7 +123,12 @@ struct WidgetSensorsAppIntentTimelineProvider: AppIntentTimelineProvider {
             throw WidgetSensorsDataError.badResponse
         }
 
-        let stateValue = (state?["state"] as? String) ?? "N/A"
+        var stateValue = (state?["state"] as? String) ?? "N/A"
+        stateValue = adjustPrecision(
+            serverId: server.identifier.rawValue,
+            entityId: sensor.entityId,
+            stateValue: stateValue
+        )
         let unitOfMeasurement = (state?["attributes"] as? [String: Any])?["unit_of_measurement"] as? String
 
         return WidgetSensorsEntry.SensorData(
@@ -135,6 +140,39 @@ struct WidgetSensorsAppIntentTimelineProvider: AppIntentTimelineProvider {
         )
     }
 
+    private func adjustPrecision(serverId: String, entityId: String, stateValue: String) -> String {
+        guard let stateValueFloat = Float(stateValue) else {
+            return stateValue
+        }
+        if let decimalPlacesForEntityId: Int = {
+            do {
+                return try Current.database.read { db in
+                    try AppEntityRegistryListForDisplay
+                        .filter(
+                            Column(DatabaseTables.AppEntityRegistryListForDisplay.id.rawValue) == ServerEntity
+                                .uniqueId(
+                                    serverId: serverId,
+                                    entityId: entityId
+                                )
+                        )
+                        .fetchOne(db)?.registry.decimalPlaces
+                }
+            } catch {
+                Current.Log.error("Failed to fetch decimal places for entity ID: \(entityId)")
+                return nil
+            }
+        }() {
+            let numberFormatter = NumberFormatter()
+            numberFormatter.numberStyle = .decimal
+            numberFormatter.locale = Locale.current
+            numberFormatter.maximumFractionDigits = decimalPlacesForEntityId
+            numberFormatter.minimumFractionDigits = decimalPlacesForEntityId
+            return numberFormatter.string(from: NSNumber(value: stateValueFloat)) ?? stateValue
+        } else {
+            return stateValue
+        }
+    }
+
     private func suggestions() async -> [(Server, [HAAppEntity])] {
         ControlEntityProvider(domains: WidgetSensorsConfig.domains).getEntities()
     }

Sources/Shared/EntityRegistryListForDisplay.swift

@@ -29,5 +29,5 @@ public struct AppEntityRegistryListForDisplay: Codable, FetchableRecord, Persist
     let id: String
     let serverId: String
     let entityId: String
-    let registry: EntityRegistryListForDisplay.Entity
+    public let registry: EntityRegistryListForDisplay.Entity
 }