fix (agents): honor configured contextWindow overrides

src/agents/context.test.ts

@@ -0,0 +1,41 @@
+import { describe, expect, it } from "vitest";
+import { applyConfiguredContextWindows } from "./context.js";
+
+describe("applyConfiguredContextWindows", () => {
+  it("overrides discovered cache values with explicit models.providers contextWindow", () => {
+    const cache = new Map<string, number>([["anthropic/claude-opus-4-6", 1_000_000]]);
+    applyConfiguredContextWindows({
+      cache,
+      modelsConfig: {
+        providers: {
+          openrouter: {
+            models: [{ id: "anthropic/claude-opus-4-6", contextWindow: 200_000 }],
+          },
+        },
+      },
+    });
+
+    expect(cache.get("anthropic/claude-opus-4-6")).toBe(200_000);
+  });
+
+  it("adds config-only model context windows and ignores invalid entries", () => {
+    const cache = new Map<string, number>();
+    applyConfiguredContextWindows({
+      cache,
+      modelsConfig: {
+        providers: {
+          openrouter: {
+            models: [
+              { id: "custom/model", contextWindow: 150_000 },
+              { id: "bad/model", contextWindow: 0 },
+              { id: "", contextWindow: 300_000 },
+            ],
+          },
+        },
+      },
+    });
+
+    expect(cache.get("custom/model")).toBe(150_000);
+    expect(cache.has("bad/model")).toBe(false);
+  });
+});