## Bug Description Admin UI at `/ui/` loads HTML successfully (HTTP 200) but JavaScript hydration never completes - stuck permanently on "🚅 LiteLLM" logo with spinning loader.

## Environment - **LiteLLM Version**: 1.83.10 (main-stable) - **Docker Image**: `ghcr.io/berriai/litellm:main-stable` - **Database**: PostgreSQL 16 - **Redis**: 7 - **OS**: macOS (Docker Desktop)

## Reproduction Steps 1. Deploy LiteLLM with Docker Compose (PostgreSQL + Redis backend) 2. Set `UI_USERNAME`, `UI_PASSWORD`, `LITELLM_MASTER_KEY` 3. Access `http://localhost:4000/ui/` 4. UI shows loading spinner indefinitely

## Observed Behavior - **HTML**: Returns 200 OK with `BAILOUT_TO_CLIENT_SIDE_RENDERING` template - **Static assets**: All JS/CSS chunks at `/litellm-asset-prefix/_next/static/` return 200 OK - **Login flow**: POST `/login` → 303 redirect → cookie set correctly (JWT with `user_role: proxy_admin`) - **API**: All API endpoints work correctly (`/user/info`, `/v1/models`, etc.) - **Client-side**: JS loads but never hydrates - no subsequent API calls observed in server logs after UI HTML load

## Server Logs (sanitized) ``` INFO: "POST /login HTTP/1.1" 303 See Other INFO: "POST /ui/?login=success H…