feat(org): add LiteLLM usage stats to organization dashboard

Replace mock token usage with real data from LiteLLM free-tier APIs
(global/activity, global/activity/model, global/spend/models). Adds
per-model breakdown table, loading/error states, usage data models
with serde tests, and i18n keys for all five languages.

Also includes: replace Ollama with LiteLLM proxy, update config,
docker-compose, and provider infrastructure.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -55,6 +55,8 @@ services:
       mongo:
         condition: service_started
     environment:
+      # LiteLLM API key (used by librechat.yaml endpoint config)
+      LITELLM_API_KEY: ${LITELLM_API_KEY:-}
       # MongoDB (use localhost since we're on host network)
       MONGO_URI: mongodb://root:example@localhost:27017/librechat?authSource=admin
       DOMAIN_CLIENT: http://localhost:3080
@@ -70,7 +72,6 @@ services:
       OPENID_CALLBACK_URL: /oauth/openid/callback
       OPENID_SCOPE: openid profile email
       OPENID_BUTTON_LABEL: Login with CERTifAI
-      OPENID_AUTH_EXTRA_PARAMS: prompt=none
       # Disable local auth (SSO only)
       ALLOW_EMAIL_LOGIN: "false"
       ALLOW_REGISTRATION: "false"