Rename solar integration types to VotronicSolarESP

Renames every type and identifier we built for the solar charge
controller bridge from generic "Solar" naming to the product name
VotronicSolarESP: VanAlignSolarProtocol -> VotronicSolarESPProtocol,
SolarSession -> VotronicSolarESPSession, SolarState ->
VotronicSolarESPState, plus the dependent properties, parameters, and
user-facing discovery/empty-state strings.

Purely a Swift-side rename - the underlying BLE service/characteristic
UUIDs are untouched, so it has no effect on communicating with the
actual firmware. DeviceRole.solar's case name, and DemoData's device
instance variables, are left as-is since they describe the role/demo
device rather than this specific integration code.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Shared/Models/ConfiguredDevice.swift

@@ -19,7 +19,7 @@ enum DeviceRole: String, Codable, CaseIterable, Identifiable, Sendable {
             //case .bms:            return "Batterie / BMS"
             //case .fridge:         return "Kühlbox"
         case .leveling:       return "Nivellierung"
-        case .solar:          return "Solarladeregler"
+        case .solar:          return "VotronicSolarESP"
         }
     }
 

Shared/Models/VotronicSolarESPState.swift

@@ -1,7 +1,7 @@
 import Foundation
 
 /// Zustand des Solarladereglers.
-struct SolarState: Equatable, Codable, Sendable {
+struct VotronicSolarESPState: Equatable, Codable, Sendable {
     var batteryVoltage: Double?
     var pvVoltage: Double?
     var pvCurrent: Double?