fix: restore Anthropic token accounting

src/agents/usage.ts

@@ -4,6 +4,17 @@ export type UsageLike = {
   cacheRead?: number;
   cacheWrite?: number;
   total?: number;
+  // Common alternates across providers/SDKs.
+  inputTokens?: number;
+  outputTokens?: number;
+  promptTokens?: number;
+  completionTokens?: number;
+  input_tokens?: number;
+  output_tokens?: number;
+  prompt_tokens?: number;
+  completion_tokens?: number;
+  cache_read_input_tokens?: number;
+  cache_creation_input_tokens?: number;
   // Some agents/logs emit alternate naming.
   totalTokens?: number;
   total_tokens?: number;
@@ -11,27 +22,58 @@ export type UsageLike = {
   cache_write?: number;
 };
 
+export type NormalizedUsage = {
+  input?: number;
+  output?: number;
+  cacheRead?: number;
+  cacheWrite?: number;
+  total?: number;
+};
+
 const asFiniteNumber = (value: unknown): number | undefined => {
   if (typeof value !== "number") return undefined;
   if (!Number.isFinite(value)) return undefined;
   return value;
 };
 
+export function hasNonzeroUsage(
+  usage?: NormalizedUsage | null,
+): usage is NormalizedUsage {
+  if (!usage) return false;
+  return [
+    usage.input,
+    usage.output,
+    usage.cacheRead,
+    usage.cacheWrite,
+    usage.total,
+  ].some((v) => typeof v === "number" && Number.isFinite(v) && v > 0);
+}
+
 export function normalizeUsage(raw?: UsageLike | null):
-  | {
-      input?: number;
-      output?: number;
-      cacheRead?: number;
-      cacheWrite?: number;
-      total?: number;
-    }
+  | NormalizedUsage
   | undefined {
   if (!raw) return undefined;
 
-  const input = asFiniteNumber(raw.input);
-  const output = asFiniteNumber(raw.output);
-  const cacheRead = asFiniteNumber(raw.cacheRead ?? raw.cache_read);
-  const cacheWrite = asFiniteNumber(raw.cacheWrite ?? raw.cache_write);
+  const input = asFiniteNumber(
+    raw.input ??
+      raw.inputTokens ??
+      raw.input_tokens ??
+      raw.promptTokens ??
+      raw.prompt_tokens,
+  );
+  const output = asFiniteNumber(
+    raw.output ??
+      raw.outputTokens ??
+      raw.output_tokens ??
+      raw.completionTokens ??
+      raw.completion_tokens,
+  );
+  const cacheRead = asFiniteNumber(
+    raw.cacheRead ?? raw.cache_read ?? raw.cache_read_input_tokens,
+  );
+  const cacheWrite = asFiniteNumber(
+    raw.cacheWrite ?? raw.cache_write ?? raw.cache_creation_input_tokens,
+  );
   const total = asFiniteNumber(
     raw.total ?? raw.totalTokens ?? raw.total_tokens,
   );