Fix: Prevent AuthManager state pollution on connection verification (#348)

* Fix: Prevent AuthManager state pollution on connection verification

Modified `ConnectViewModel.connect()` to construct a temporary OkHttpClient and Retrofit builder, isolated from the global `ApiClient` state. The connection verification is executed using this temporary service. Only upon a successful HTTP response does the system persist the configured `host`, `port`, and `token` to the global `AuthManager` and triggers an `ApiClient.rebuild()`. This resolves the issue where a failed connection attempt would overwrite active and verified profiles. Extracted `createTempService` factory to `ApiClient` for robustness and clean tests.

Fixes #260

* Fix: Prevent AuthManager state pollution on connection verification

Modified `ConnectViewModel.connect()` to construct a temporary OkHttpClient and Retrofit builder, isolated from the global `ApiClient` state. The connection verification is executed using this temporary service. Only upon a successful HTTP response does the system persist the configured `host`, `port`, and `token` to the global `AuthManager` and triggers an `ApiClient.rebuild()`. This resolves the issue where a failed connection attempt would overwrite active and verified profiles. Extracted `createTempService` factory to `ApiClient` for robustness and clean tests.

Fixes #260

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Co-authored-by: M57 <hy4ri@users.noreply.github.com>

app/src/test/java/com/m57/hermescontrol/E2eIntegrationTest.kt

@@ -72,6 +72,7 @@ class E2eIntegrationTest {
 
         mockApiService = mockk()
         every { ApiClient.hermesApi } returns mockApiService
+        every { ApiClient.createTempService(any(), any(), any()) } returns mockApiService
         every { ApiClient.rebuild() } returns Unit
 
         // Default AuthManager stubs
@@ -774,7 +775,6 @@ class E2eIntegrationTest {
             assertEquals("Invalid token (401 Unauthorized)", viewModel.uiState.value.errorMessage)
             assertFalse(viewModel.uiState.value.connectionSuccess)
             // Verify AuthManager.setToken(null) was called
-            verify { AuthManager.setToken(null) }
         }
 
     // ── Tier 4: Real-World Scenarios ─────────────────────────────────────