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/main/res/values/strings.xml

@@ -178,7 +178,6 @@
     <string name="connect_error_refused">Connection refused – is Hermes running?</string>
     <string name="connect_error_resolve">Could not resolve host</string>
     <string name="connect_error_connection_failed">Connection failed: %1$s</string>
-    <string name="connect_error_invalid_host">Invalid or forbidden host in pairing string</string>
     <string name="connect_error_missing_fields">Malformed pairing string — missing host, port, or token</string>
     <string name="connect_error_malformed">Malformed pairing string — expected URL or Base64-encoded JSON</string>
     <string name="connect_error_parse_failed">Failed to parse pairing string: %1$s</string>