chore: import upstream snapshot with attribution

docs/llm-proxy.md

@@ -0,0 +1,41 @@
+---
+summary: "LLM Proxy provider setup and quota-stats usage source."
+read_when:
+  - Configuring LLM Proxy usage tracking
+  - Debugging aggregate proxy quota or provider breakdown display
+---
+
+# LLM Proxy
+
+CodexBar reads aggregate usage from an LLM-API-Key-Proxy compatible `/v1/quota-stats` endpoint.
+
+## Setup
+
+Store the API key:
+
+```bash
+printf '%s' "$LLM_PROXY_API_KEY" | codexbar config set-api-key --provider llmproxy --stdin
+```
+
+Set the base URL with `LLM_PROXY_BASE_URL`, or add `enterpriseHost` to the provider config:
+
+```json
+{
+  "id": "llmproxy",
+  "enabled": true,
+  "apiKey": "<REDACTED>",
+  "enterpriseHost": "https://proxy.example.com"
+}
+```
+
+The base URL may point at either the service root or `/v1`; CodexBar normalizes both to `/v1/quota-stats`.
+
+## Menu display
+
+- Primary: lowest remaining quota group, rendered as percent used.
+- Secondary: total requests.
+- Tertiary: total tokens.
+- Extra rows: top provider summaries by request count.
+- Cost: approximate spend when the proxy reports `approx_cost`.
+
+`quota_groups` may be either an array or a keyed object; CodexBar accepts both shapes.