Fix/combo multimodal capability 13847 (#13863)

* fix(capabilities): align combo multimodal vision hints

* test(capabilities): cover combo multimodal consistency

* chore(changelog): note combo multimodal capability fix

tests/unit/combo-multimodal-capability-13847.test.ts

@@ -0,0 +1,51 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { getResolvedModelCapabilities } from "../../src/lib/modelCapabilities.ts";
+import { computeComboCapabilities } from "../../src/app/api/v1/combos/projectCombo.ts";
+
+const REPORTED_VISION_MEMBERS = [
+  "opencode-go/mimo-v2.5",
+  "kilo-gateway/stepfun/step-3.7-flash:free",
+  "opencode-zen/mimo-v2.5-free",
+  "opencode/mimo-v2.5-free",
+  "command-code/xiaomi/mimo-v2.5",
+] as const;
+
+test("#13847 reported combo members resolve as vision-capable", () => {
+  for (const model of REPORTED_VISION_MEMBERS) {
+    assert.equal(
+      getResolvedModelCapabilities(model).supportsVision,
+      true,
+      `${model} should retain its vision capability through provider/free-route qualification`
+    );
+  }
+});
+
+test("#13847 known MiMo Pro text-only siblings stay excluded", () => {
+  for (const model of [
+    "mimo-v2.5-pro",
+    "command-code/xiaomi/mimo-v2.5-pro",
+    "mimo-v2-pro",
+  ]) {
+    assert.notEqual(
+      getResolvedModelCapabilities(model).supportsVision,
+      true,
+      `${model} must not inherit the MiMo V2.5 multimodal heuristic`
+    );
+  }
+});
+
+test("#13847 combo projection agrees with vision-capable members", () => {
+  const combo = {
+    name: "default-observer",
+    strategy: "priority",
+    models: REPORTED_VISION_MEMBERS.map((model) => ({ kind: "model", model })),
+  };
+
+  assert.deepEqual(computeComboCapabilities(combo), {
+    multimodal: true,
+    reasoning: true,
+    caching: false,
+  });
+});