Add public API unit tests with ≥80% coverage (#30)

Expand ReliaBLETests to exercise every public method and property on
ReliaBLEManager plus the public value types, closing NFR-2.1 (#30).

- Drive authorization, scanning, discovery, and connection paths through
  Nordic's CBMCentralManagerMock via the existing three-target SPM trick
  (forceMock: true), with no real CoreBluetooth hardware.
- Unify all tests into a single @suite(.serialized): the process-wide
  BluetoothActor singleton and the mock's global state make parallel
  execution unsafe (a scan in one test would feed another's discovery
  subscriber). A one-shot SimulationConfig registers the simulated
  peripheral and pins authorization before any central is created, and
  an ensureReady helper re-establishes a known baseline per test, so the
  suite is order-independent.
- Cover the public value types directly: BluetoothState.description for
  every case, Peripheral/PeripheralDiscoveryEvent id-based equality and
  hashing, AdvertisementData typed extraction, ReliaBLEConfig defaults,
  and the logging module (LoggingService, LogMessage, OSLogWriter).
- Add CoreBluetoothMock and Willow as test-target dependencies.

Measured coverage of Sources/ReliaBLE/: 91.76% line / 87.89% region
(ReliaBLEManager 100%, BluetoothActor 87.7% line). swift test passes
with zero failures.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: itsniper

Package.swift

@@ -35,7 +35,11 @@ let package = Package(
         ),
         .testTarget(
             name: "ReliaBLETests",
-            dependencies: ["ReliaBLEMock"],
+            dependencies: [
+                "ReliaBLEMock",
+                "Willow",
+                .product(name: "CoreBluetoothMock", package: "IOS-CoreBluetooth-Mock")
+            ],
             swiftSettings: [.swiftLanguageMode(.v6), .enableExperimentalFeature("StrictConcurrency")]
         ),
     ]