refactor: remove device Pairing feature entirely (issue #645) (#650)

* refactor: remove device Pairing feature entirely (issue #645)

- Delete Pairing.kt model + pairing API endpoints (get/approve/revoke/clear)
- Delete PairingScreen/PairingViewModel + PairingCodeEntryScreen/ViewModel
- Remove NavKeys, ScreenRegistry drawer entry, Navigation.kt entry + Landing pairing button
- Remove pairing string resources (en + ko); keep connect_* config-parse strings
- Keep Telegram onboarding pairing_id flow (separate concept, per issue)
- Fix related doc comments + remaining test reference

* test: fix racy CONNECTED read in gated-mode WS test (issue #635 test)

testGatedMode_attemptsTicketFetchWithoutBareCookie asserted CONNECTED
immediately after the server-side onOpen latch fired, racing the client
handshake (WsListenerImpl sets CONNECTED on receipt of the 101). Await the
real status transition via connectionStatus.first{==CONNECTED} like the
other connect tests do. No product behavior changed.

---------

Co-authored-by: M57 <Hy4ri@users.noreply.github.com>

app/src/test/java/com/m57/hermescontrol/data/ws/HermesWsClientTest.kt

@@ -542,6 +542,15 @@ class HermesWsClientTest {
             "Gated WS ticket fetch should be attempted even without a bare cookie",
             connectLatch.await(5, TimeUnit.SECONDS),
         )
+        // The server-side onOpen latch fires a hair before the client receives
+        // the 101 handshake and WsListenerImpl sets CONNECTED — await the real
+        // status transition (as every other connect test does) instead of a
+        // racy read that can observe CONNECTING.
+        runBlocking {
+            withTimeout(5000) {
+                HermesWsClient.connectionStatus.first { it == ConnectionStatus.CONNECTED }
+            }
+        }
         assertEquals(ConnectionStatus.CONNECTED, HermesWsClient.connectionStatus.value)
 
         ticketServer.shutdown()