Fetch all provider configs (Gemini, Claude, Codex, Vertex, OpenAI) and
compute SHA-256 auth_index from their API keys to map unresolved
credential entries to friendly provider names.
Add Claude quota section to the Quota Management page, using the
Anthropic OAuth usage API (api.anthropic.com/api/oauth/usage) to
display utilization across all rate limit windows (5-hour, 7-day,
Opus, Sonnet, etc.) and extra usage credits.