Add solar charge controller integration and firmware

App:
- New DeviceRole.solar with its own BLE session/protocol/state
  (SolarSession, VanAlignSolarProtocol, SolarState), mirroring the
  leveling sensor but deliberately not wired into the Live Activity.
- BluetoothManager now keeps an in-memory history per metric (voltage,
  current, power) instead of a single primary-metric series; cleared on
  app restart by design, not persisted to disk.
- DeviceDetailView shows a channel picker above the history chart when a
  device has more than one chartable metric.
- AddDeviceView recognizes the solar service UUID during setup.
- DemoData gets a simulated solar device so the integration can be
  checked in the simulator without hardware.

Firmware:
- Add esp32_ble_solar.yaml (Votronic solar charge controller over BLE)
  and simulated variants (esp32_ble_sim.yaml, esp32_ble_solar_sim.yaml)
  for testing without a vehicle.
- esp32_ble.yaml: set flash_size/psram for the ESP32-S3 N16R8 module.

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

Shared/Bluetooth/VanAlignSolarProtocol.swift

@@ -0,0 +1,55 @@
+import Foundation
+
+/// Solarladeregler „VanAlign Solar" – zweiter ESP32 im Fahrzeug, liest einen
+/// Votronic-Solarladeregler aus und stellt die Werte über einen eigenen
+/// BLE-Dienst bereit. Siehe `firmware/vanalign/esp32_ble_solar.yaml`.
+///
+/// Wie beim Neigungsmesser: kein Rahmenprotokoll, jede Messgrösse liegt in
+/// einer eigenen Charakteristik, alle sind reine Lesewerte, der Client fragt
+/// sie im Takt ab.
+enum VanAlignSolarProtocol {
+
+    /// Wird vom Gerät beworben, das Gerät ist darüber auffindbar.
+    static let serviceUUID = "05C9A349-2B8E-4B1D-9C9D-C247E9A6A001"
+
+    static let batteryVoltageUUID = "05C9A349-2B8E-4B1D-9C9D-C247E9A6A101"
+    static let pvVoltageUUID      = "05C9A349-2B8E-4B1D-9C9D-C247E9A6A102"
+    static let pvCurrentUUID      = "05C9A349-2B8E-4B1D-9C9D-C247E9A6A103"
+    static let pvPowerUUID        = "05C9A349-2B8E-4B1D-9C9D-C247E9A6A104"
+    static let controllerTempUUID = "05C9A349-2B8E-4B1D-9C9D-C247E9A6A105"
+    /// Bit0 Batterie lädt, Bit1 Batterie entlädt, Bit2 PV-Regler aktiv,
+    /// Bit3 PV-Strombegrenzung, Bit4 AES aktiv.
+    static let statusFlagsUUID    = "05C9A349-2B8E-4B1D-9C9D-C247E9A6A106"
+
+    /// Liest einen Messwert aus vier Bytes, little-endian – wie beim
+    /// Neigungsmesser legt die Firmware den Float per `memcpy` ab.
+    static func float(from data: Data) -> Double? {
+        guard data.count >= 4 else { return nil }
+        var raw: UInt32 = 0
+        for (index, byte) in data.prefix(4).enumerated() {
+            raw |= UInt32(byte) << UInt32(8 * index)
+        }
+        let value = Float(bitPattern: raw)
+        guard value.isFinite else { return nil }
+        return Double(value)
+    }
+
+    struct StatusFlags {
+        var isBatteryCharging = false
+        var isBatteryDischarging = false
+        var isControllerActive = false
+        var isCurrentLimited = false
+        var isAESActive = false
+    }
+
+    static func statusFlags(from data: Data) -> StatusFlags? {
+        guard let byte = data.first else { return nil }
+        var flags = StatusFlags()
+        flags.isBatteryCharging = byte & (1 << 0) != 0
+        flags.isBatteryDischarging = byte & (1 << 1) != 0
+        flags.isControllerActive = byte & (1 << 2) != 0
+        flags.isCurrentLimited = byte & (1 << 3) != 0
+        flags.isAESActive = byte & (1 << 4) != 0
+        return flags
+    }
+}