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>

Cargo.lock

@@ -773,6 +773,7 @@ dependencies = [
  "dioxus-sdk",
  "dotenvy",
  "futures",
+ "js-sys",
  "maud",
  "mongodb",
  "petname",