Complete Better Auth migration, harden security, update all docs

Console:
- Rewrite auth from JWT decoding to Better Auth useSession()
- Add auth-client.ts with createAuthClient
- Remove elydora_token localStorage, dead auth API functions
- Fix login/register pages to use signIn.email/signUp.email

Server:
- Upgrade better-auth ^1.2.0 → ^1.5.5
- CORS: enforce allowlist on all environments
- Sync auth service and middleware with backend

SDKs:
- Deprecate login/register in Node, Python, Go SDKs
- Update READMEs to show direct token initialization

Config:
- Sanitize .env with dev-only placeholder values
- Update helm chart and install scripts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/console/src/app/login/page.tsx

@@ -3,14 +3,12 @@
 import { useState } from 'react';
 import { useRouter } from 'next/navigation';
 import Link from 'next/link';
-import { api } from '@/lib/api';
-import { useAuth } from '@/lib/auth';
+import { signIn } from '@/lib/auth-client';
 import { useTranslation } from 'react-i18next';
 
 export default function LoginPage() {
   const { t } = useTranslation();
   const router = useRouter();
-  const { login } = useAuth();
   const [email, setEmail] = useState('');
   const [password, setPassword] = useState('');
   const [error, setError] = useState('');
@@ -21,8 +19,10 @@ export default function LoginPage() {
     setError('');
     setIsSubmitting(true);
     try {
-      const result = await api.auth.login(email, password);
-      login(result.token, { display_name: result.user.display_name, email: result.user.email });
+      const result = await signIn.email({ email, password });
+      if (result.error) {
+        throw new Error(result.error.message ?? t('login.loginFailed'));
+      }
       router.push('/');
     } catch (err) {
       setError(err instanceof Error ? err.message : t('login.loginFailed'));

packages/console/src/app/register/page.tsx

@@ -3,14 +3,12 @@
 import { useState } from 'react';
 import { useRouter } from 'next/navigation';
 import Link from 'next/link';
-import { api } from '@/lib/api';
-import { useAuth } from '@/lib/auth';
+import { signUp } from '@/lib/auth-client';
 import { useTranslation } from 'react-i18next';
 
 export default function RegisterPage() {
   const { t } = useTranslation();
   const router = useRouter();
-  const { login } = useAuth();
   const [email, setEmail] = useState('');
   const [password, setPassword] = useState('');
   const [displayName, setDisplayName] = useState('');
@@ -23,8 +21,10 @@ export default function RegisterPage() {
     setError('');
     setIsSubmitting(true);
     try {
-      const result = await api.auth.register(email, password, displayName, orgName);
-      login(result.token, { display_name: result.user.display_name, email: result.user.email });
+      const result = await signUp.email({ email, password, name: displayName });
+      if (result.error) {
+        throw new Error(result.error.message ?? t('register.registrationFailed'));
+      }
       router.push('/');
     } catch (err) {
       setError(err instanceof Error ? err.message : t('register.registrationFailed'));