feat(panel): implement email otp and passkey login interface

panel/src/i18n/resources/en-US/auth.json

@@ -1,12 +1,28 @@
 {
   "login_title": "Sign in to Felis",
   "login_subtitle": "Operator console",
-  "username": "Username",
+  "username": "Username or Email",
   "password": "Password",
   "sign_in": "Sign in",
   "signing_in": "Signing in…",
   "tab_password": "Password",
   "tab_bind": "Bind Code",
+  "tab_email": "Email OTP",
+  "other_login_methods": "Other sign-in options",
+  "or_divider": "or",
+  "tab_email_btn": "Sign in with Email OTP",
+  "tab_bind_btn": "Sign in with Bind Code",
+  "back_to_password": "Back to password login",
+  "email_address": "Email Address",
+  "email_placeholder": "Enter your registered email",
+  "otp_code": "Verification Code",
+  "otp_placeholder": "Enter 6-digit code",
+  "send_otp": "Send Code",
+  "sending_otp": "Sending…",
+  "otp_sent": "Verification code sent to your email.",
+  "otp_btn": "Verify & Sign In",
+  "resend_in": "s",
+  "passkey_btn": "Sign in with Passkey",
   "bind_code": "Bind Code",
   "bind_code_placeholder": "e.g., ABCD2345",
   "bind_hint": "Type /login in-game to generate a one-time bind code.",

panel/src/i18n/resources/en-US/errors.json

@@ -25,5 +25,7 @@
   "passkey_challenge_invalid": "Passkey challenge is invalid or expired, please try again.",
   "invalid_attestation": "Could not verify this Passkey, please try again.",
   "passkey_already_bound": "This Passkey is already bound to another account.",
-  "passkey_unavailable": "Passkey subsystem is not available right now."
+  "passkey_unavailable": "Passkey subsystem is not available right now.",
+  "passkey_not_allowed": "The operation was cancelled by the user or browser.",
+  "passkey_aborted": "Passkey registration was aborted."
 }