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>

sdks/node/package-lock.json

@@ -1,13 +1,16 @@
 {
   "name": "@elydora/sdk",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@elydora/sdk",
-      "version": "1.0.0",
+      "version": "1.1.0",
       "license": "MIT",
+      "bin": {
+        "elydora": "dist/cli.js"
+      },
       "devDependencies": {
         "@types/node": "^22.0.0",
         "typescript": "^5.7.0"