refactor(infra): split provider usage

src/infra/provider-usage.fetch.copilot.ts

@@ -0,0 +1,70 @@
+import { fetchJson } from "./provider-usage.fetch.shared.js";
+import { clampPercent, PROVIDER_LABELS } from "./provider-usage.shared.js";
+import type {
+  ProviderUsageSnapshot,
+  UsageWindow,
+} from "./provider-usage.types.js";
+
+type CopilotUsageResponse = {
+  quota_snapshots?: {
+    premium_interactions?: { percent_remaining?: number | null };
+    chat?: { percent_remaining?: number | null };
+  };
+  copilot_plan?: string;
+};
+
+export async function fetchCopilotUsage(
+  token: string,
+  timeoutMs: number,
+  fetchFn: typeof fetch,
+): Promise<ProviderUsageSnapshot> {
+  const res = await fetchJson(
+    "https://api.github.com/copilot_internal/user",
+    {
+      headers: {
+        Authorization: `token ${token}`,
+        "Editor-Version": "vscode/1.96.2",
+        "User-Agent": "GitHubCopilotChat/0.26.7",
+        "X-Github-Api-Version": "2025-04-01",
+      },
+    },
+    timeoutMs,
+    fetchFn,
+  );
+
+  if (!res.ok) {
+    return {
+      provider: "github-copilot",
+      displayName: PROVIDER_LABELS["github-copilot"],
+      windows: [],
+      error: `HTTP ${res.status}`,
+    };
+  }
+
+  const data = (await res.json()) as CopilotUsageResponse;
+  const windows: UsageWindow[] = [];
+
+  if (data.quota_snapshots?.premium_interactions) {
+    const remaining =
+      data.quota_snapshots.premium_interactions.percent_remaining;
+    windows.push({
+      label: "Premium",
+      usedPercent: clampPercent(100 - (remaining ?? 0)),
+    });
+  }
+
+  if (data.quota_snapshots?.chat) {
+    const remaining = data.quota_snapshots.chat.percent_remaining;
+    windows.push({
+      label: "Chat",
+      usedPercent: clampPercent(100 - (remaining ?? 0)),
+    });
+  }
+
+  return {
+    provider: "github-copilot",
+    displayName: PROVIDER_LABELS["github-copilot"],
+    windows,
+    plan: data.copilot_plan,
+  };
+}