feat(web): full auth screens rework to match design + old-app business rules

Rebuilt tenant/login/register/reset-password to match the design handoff's
01-account screens precisely (previously only loosely approximated), and
ported the old app's real business rules instead of guessing:

- LoginPage: desktop split branding panel (>=900px), terms-agreement
  checkbox gating submit, forgot-password link, password visibility toggle,
  full ctrl-error translation table (lib/tinode/errors.ts, ported from the
  old app's CTRL_ERROR_TEXT_CN/translateCtrlError -- registration/login go
  over native WS, not REST, so client.ts's REASON_MESSAGES never applied).
- RegisterPage: rebuilt as the real unified username-OR-phone form (not
  phone-only) -- username optional unless phone is blank, invite code
  required+validated only on the username-only path, matching the server's
  actual resolveRegistrationAccount rules. connection.ts's
  registerAccountByPhone generalized into registerAccount() supporting both
  paths, including the Tinode.credential(null) crash the old app had to
  work around on the username-only path.
- New ResetPasswordPage wired to /auth/password-reset/* (a different
  endpoint family than registration's /auth/verification-codes/*).
- Shared components: PasswordInput, VerificationCodeButton, Agreement,
  Toast.
- Fixed tinode-sdk.d.ts: the real method is getCurrentUserID(), not the
  invented getAuthenticatedUserID() -- caught live, login crashed past a
  successful auth.
- Fixed a responsive bug present on all four auth pages: fixed w-[380px]
  forms overflowed past the viewport edge below ~430px wide.

Verified end-to-end against the real backend (api.118im.com, tenant
"default"): fresh phone registration, password reset, re-login with the
new password, and the username-only path's invite-code rejection all
round-tripped correctly.

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

web/src/features/auth/components/PasswordInput.tsx

@@ -0,0 +1,43 @@
+import { useState } from 'react';
+
+import { Icon } from '@/app/Icon';
+
+interface PasswordInputProps {
+  value: string;
+  onChange: (value: string) => void;
+  placeholder: string;
+  autoComplete?: string;
+  error?: string;
+}
+
+export function PasswordInput({ value, onChange, placeholder, autoComplete, error }: PasswordInputProps) {
+  const [visible, setVisible] = useState(false);
+
+  return (
+    <div className="flex flex-col gap-1.5">
+      <div
+        className={`flex h-[50px] items-center rounded-lg bg-surface-input px-3.5 has-focus:border has-focus:shadow-focus-ring ${
+          error ? 'border border-danger-border' : 'has-focus:border-focus-border'
+        }`}
+      >
+        <input
+          type={visible ? 'text' : 'password'}
+          value={value}
+          onChange={(e) => onChange(e.target.value)}
+          placeholder={placeholder}
+          autoComplete={autoComplete}
+          className="w-full bg-transparent text-[15px] outline-none"
+        />
+        <button
+          type="button"
+          onClick={() => setVisible((v) => !v)}
+          aria-label={visible ? '隐藏密码' : '显示密码'}
+          className="text-text-placeholder-1"
+        >
+          <Icon name={visible ? 'visibility' : 'visibility_off'} className="text-[20px]" />
+        </button>
+      </div>
+      {error ? <div className="text-xs text-danger-border">{error}</div> : null}
+    </div>
+  );
+}