fix(smc): correct IOKit service name and SMCKeyData_t layout (fixes #32)

Two latent bugs kept all SMC telemetry dead:
- IOServiceMatching("AppleSMCClient") never matched — the kernel service
  is AppleSMC, so openWithError always failed and every SMC-gated provider
  (thermal, fan, component, power) reported unavailable.
- #pragma pack(1) shrank SMCKeyData_t to 74 bytes; the SMC user client
  requires the canonical 80-byte layout and rejected every
  IOConnectCallStructMethod with kIOReturnBadArgument. Verified live on
  Intel hardware: unpacked calls succeed and return key data.

Also sources the alert engine's batteryLevel from the SMC-independent
batteryHealth path (currentCapacity/maxCapacity), falling back to the
power provider.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Sources/App/SystemTelemetryStore.swift

@@ -705,7 +705,9 @@ public final class SystemTelemetryStore {
                     : 0
             )
         }
-        context.batteryLevel = self.power.batteryLevel
+        context.batteryLevel = self.batteryHealth.maxCapacity > 0
+            ? Double(self.batteryHealth.currentCapacity) / Double(self.batteryHealth.maxCapacity) * 100.0
+            : self.power.batteryLevel
         context.hasBattery = self.batteryHealth.hasBattery
         context.onExternalPower = self.batteryHealth.externalConnected
         context.isCharging = self.batteryHealth.isCharging || self.power.isCharging

Sources/Hardware/AppleSMC/MMAppleSMCClient.m

@@ -57,13 +57,13 @@
         return YES;
     }
     
-    CFMutableDictionaryRef matching = IOServiceMatching("AppleSMCClient");
+    CFMutableDictionaryRef matching = IOServiceMatching("AppleSMC");
     if (!matching) {
         os_unfair_lock_unlock(&_lock);
         if (error) {
             *error = [NSError errorWithDomain:@"com.i3omb.MacMonitor.SMC"
                                          code:-1
-                                     userInfo:@{NSLocalizedDescriptionKey: @"Failed to create AppleSMCClient matching dictionary"}];
+                                     userInfo:@{NSLocalizedDescriptionKey: @"Failed to create AppleSMC matching dictionary"}];
         }
         return NO;
     }
@@ -74,7 +74,7 @@
         if (error) {
             *error = [NSError errorWithDomain:@"com.i3omb.MacMonitor.SMC"
                                          code:-2
-                                     userInfo:@{NSLocalizedDescriptionKey: @"AppleSMCClient service not found (running on non-Mac or unsupported VM)"}];
+                                     userInfo:@{NSLocalizedDescriptionKey: @"AppleSMC service not found (running on non-Mac or unsupported VM)"}];
         }
         return NO;
     }

Sources/Hardware/AppleSMC/MMSMCDefines.h

@@ -15,8 +15,6 @@
 #define kSMCGetKeyFromIndex 8
 #define kSMCGetKeyInfo      9
 
-#pragma pack(push, 1)
-
 typedef struct {
     unsigned char major;
     unsigned char minor;
@@ -58,8 +56,6 @@ typedef struct {
     UInt8 bytes[32];
 } SMCVal_t;
 
-#pragma pack(pop)
-
 static inline UInt32 MMSMCToFourCharCode(const char * _Nonnull str) {
     UInt32 code = 0;
     for (int i = 0; i < 4 && str[i] != '\0'; i++) {