feat(android): QR pairing — scan, deep link, one-step auto-login

Companion side of docs/companion-pairing-qr.md (v1 contract):
- Connect screen lands on Scan Node's QR / Enter Manually; NESMenu gains
  an add-server-by-QR icon button
- QrScannerOverlay: CameraX + ZXing core (pinned, on-device, no ML Kit)
- ServerQrParser: archipelago://pair?v=1&url=..[&pw=..]; unknown major v
  -> 'update the app'; upsert by origin so re-scans never duplicate
- archipelago:// deep link registered (singleTask + onNewIntent) for the
  modal's 'Open in companion app' button
- WebView auto-fills and submits Login.vue's password form when a stored
  password exists — demo QR is one step to a logged-in session
- Web modal + handoff doc copy synced to the real label: Scan Node's QR
- v0.4.13 (versionCode 17)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

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

@@ -29,6 +29,15 @@
     <string name="server_name_label">Server Name (optional)</string>
     <string name="server_name_placeholder">My Archipelago</string>
     <string name="edit_server">Edit</string>
+    <string name="scan_node_qr">Scan Node\'s QR</string>
+    <string name="enter_manually">Enter Manually</string>
+    <string name="connect_landing_hint">Scan the pairing QR from your node\'s Companion popup, or enter the address manually</string>
+    <string name="scan_qr_hint">Point the camera at the pairing QR shown in the Companion popup</string>
+    <string name="camera_permission_needed">Camera access is needed to scan the pairing QR. You can also enter the server details manually.</string>
+    <string name="grant_camera_access">Grant Camera Access</string>
+    <string name="invalid_pairing_qr">Not an Archipelago pairing code</string>
+    <string name="update_app_for_qr">This pairing code needs a newer app version — please update the companion app</string>
+    <string name="add_server_qr">Add server by QR</string>
     <string name="edit_server_title">Edit Server</string>
     <string name="save_changes">Save Changes</string>
     <string name="cancel">Cancel</string>