Update all imports of TokenConfig and EndpointTokenConfig to import
directly from librechat-data-provider instead of re-exporting through
packages/api/src/types/tokens.ts. Remove the now-unnecessary re-export
file and its barrel export.
Add TokenUsageIndicator component with circular progress ring
Create useTokenUsage hook with Jotai atom for state
Add model context window lookups to data-provider
Consolidate token utilities (output limits, TOKEN_DEFAULTS)
Display input/output tokens and percentage of context used