feat(login): replace Facebook with email-password auth screen

- Remove Facebook provider from Login flow
- Add EmailLoginScreen with gradient background, email/password fields
- Add EmailLoginScreenContract and EmailLoginViewModel with stub logic
- Add navigation: Sign in with email -> EmailLoginScreen
- Use back arrow icon instead of back text
- Move header above email field, add Register button
- Update run command to launch app after install
- Add ic_arrow_back drawable, update strings

Made-with: Cursor

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

@@ -81,7 +81,7 @@
     <string name="button_cancel">Cancel</string>
     <string name="button_register">Register</string>
     <string name="button_sign_in_google">Sign in with Google</string>
-    <string name="button_sign_in_facebook">Sign in with Facebook</string>
+    <string name="button_sign_in_email">Sign in with email</string>
     <string name="button_copy_log">Copy log</string>
     <string name="button_look_for_device">Look for a device</string>
     <string name="button_finish">Finish</string>
@@ -92,7 +92,10 @@
     <string name="button_setup">Add new device</string>
     <string name="button_connecting">Connecting…</string>
 
+    <string name="text_sign_in_email">Sign in with email</string>
+
     <!-- Hints -->
+    <string name="hint_email">Email</string>
     <string name="hint_password">Password</string>
     <string name="hint_device_name">Device name</string>
     <string name="hint_setup_name">Name</string>
@@ -142,8 +145,6 @@
     <string name="toast_copied">Copied</string>
     <string name="snackbar_not_registered">Device requires registration</string>
 
-    <string name="facebook_app_id" translatable="false">356744979027664</string>
-    <string name="fb_login_protocol_scheme" translatable="false">fb356744979027664</string>
     <string name="text_air_quality">Air quality</string>
     <string name="pref_fullscreen">Borderless layout</string>
     <string name="text_error">Error</string>