feat(aiturk): reach the IDE through an end-to-end encrypted tunnel

A phone on the same Wi-Fi could not reach the computer at all (client
isolation on the router), and every failure was shown as one 'same
Wi-Fi' message. Contract v3: the phone only dials turkservis.online.

Transport: a relay pairing lives on the virtual host
<relayId>.relay.aiturk.invalid. For that host only, the shared OkHttp
client resolves a placeholder address, opens a WebSocket byte stream to
the relay instead of a TCP connection, and runs TLS on top of it pinned
to the IDE's certificate fingerprint. The relay sees ciphertext only.
DNS, sockets, proxy choice and TLS are unchanged for every other host.

Pairing: tunnel first (hello within 10 s), LAN candidates second, one
claim only. The local-network permission is requested only when a LAN
address may be tried; denying it no longer ends the pairing.

Errors: host offline, unknown relay, busy, no internet, silent computer,
certificate mismatch and the LAN failures each get their own text plus
a short diagnostic code built from a fixed vocabulary (never a token,
pairing code or address). After pairing the screen shows the first 8
characters of the fingerprint as a security code.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B8ppceaR5s6cvMnm7uGRnf

app/src/main/res/values/strings.xml

@@ -1866,7 +1866,7 @@
     <!-- AITURK IDE pairing (QR / code) -->
     <string name="landing_action_aiturk_pair">Connect to computer (QR / code)</string>
     <string name="aiturk_pair_title">Connect to your computer</string>
-    <string name="aiturk_pair_desc">On your computer open AITURK IDE → Settings → Phone connection. Scan the QR code shown there or type the 8-character code. The phone and the computer must be on the same Wi-Fi.</string>
+    <string name="aiturk_pair_desc">On your computer open AITURK IDE → Settings → Phone connection. Scan the QR code shown there or type the 8-character code. It works from anywhere with internet; the same Wi-Fi is not required. The computer must be on with AITURK IDE running.</string>
     <string name="aiturk_pair_scan_qr">Scan QR</string>
     <string name="aiturk_pair_scan_prompt">Point the camera at the QR code in AITURK IDE</string>
     <string name="aiturk_pair_or">or</string>
@@ -1878,9 +1878,9 @@
     <string name="aiturk_pair_progress_resolve">Looking up the code…</string>
     <string name="aiturk_pair_progress_connect">Connecting to your computer…</string>
     <string name="aiturk_pair_confirm_title">Connect to this computer?</string>
-    <string name="aiturk_pair_confirm_message">A link is asking AITURK Mobil to connect to the computer at %1$s on your network. Continue only if you opened this link yourself from AITURK IDE.</string>
+    <string name="aiturk_pair_confirm_message">A link is asking AITURK Mobil to connect to the computer at %1$s. Continue only if you opened this link yourself from AITURK IDE.</string>
     <string name="aiturk_pair_error_camera_denied">Camera permission was not granted. You can type the 8-character code instead.</string>
-    <string name="aiturk_pair_error_lan_permission">Access to devices on your local network was not allowed. Allow it to connect to your computer.</string>
+    <string name="aiturk_pair_error_lan_permission">Access to devices on your local network was not allowed, so the computer could not be reached over Wi-Fi. Allow the permission in the phone\'s settings and try again.</string>
     <string name="aiturk_pair_error_qr_not_aiturk">This is not an AITURK pairing QR code.</string>
     <string name="aiturk_pair_error_update_app">This QR code needs a newer AITURK Mobil. Please update the app.</string>
     <string name="aiturk_pair_error_qr_invalid">The QR code is incomplete or damaged. Open Phone connection in AITURK IDE again and retry.</string>
@@ -1894,4 +1894,16 @@
     <string name="aiturk_pair_error_pairing_locked">Too many wrong codes, pairing was cancelled. Start Phone connection again in AITURK IDE.</string>
     <string name="aiturk_pair_error_unexpected">The computer gave an unexpected answer. Update AITURK IDE and AITURK Mobil, then try again.</string>
     <string name="aiturk_pair_error_save_failed">Paired, but the connection could not be saved. Please try again.</string>
+    <string name="aiturk_pair_error_host_offline">AITURK IDE is not open on the computer, or Phone connection is turned off. Open AITURK IDE, turn on Phone connection and try again.</string>
+    <string name="aiturk_pair_error_host_timeout">The computer did not answer. Check that AITURK IDE is running and try again.</string>
+    <string name="aiturk_pair_error_relay_busy">Too many connections. Try again in a moment.</string>
+    <string name="aiturk_pair_error_relay_unknown">This pairing is no longer valid. Pair again from AITURK IDE.</string>
+    <string name="aiturk_pair_error_tls_pin">The computer\'s identity could not be verified. Pair again from AITURK IDE.</string>
+    <string name="aiturk_pair_security_title">Connected</string>
+    <string name="aiturk_pair_security_message">Security code: %1$s\n\nIt should match the security code shown under the QR code in AITURK IDE. The connection is end-to-end encrypted.</string>
+    <string name="aiturk_pair_security_ok">OK</string>
+    <string name="aiturk_pair_error_no_internet">The internet could not be reached. Check the phone\'s Wi-Fi or mobile data and try again.</string>
+    <string name="aiturk_pair_error_relay">Connection error. Try again in a moment; if it continues, update AITURK IDE and AITURK Mobil.</string>
+    <string name="aiturk_pair_error_code">Diagnostic code: %1$s</string>
+    <string name="aiturk_status_host_offline">AITURK IDE is not open on the computer, or Phone connection is turned off</string>
 </resources>