fix: add gemini 3.1 flash-lite support

src/config/defaults.ts

@@ -30,6 +30,7 @@ const DEFAULT_MODEL_ALIASES: Readonly<Record<string, string>> = {
   // Google Gemini (3.x are preview ids in the catalog)
   gemini: "google/gemini-3.1-pro-preview",
   "gemini-flash": "google/gemini-3-flash-preview",
+  "gemini-flash-lite": "google/gemini-3.1-flash-lite-preview",
 };
 
 const DEFAULT_MODEL_COST: ModelDefinitionConfig["cost"] = {

src/config/model-alias-defaults.test.ts

@@ -69,6 +69,7 @@ describe("applyModelDefaults", () => {
           models: {
             "google/gemini-3.1-pro-preview": { alias: "" },
             "google/gemini-3-flash-preview": {},
+            "google/gemini-3.1-flash-lite-preview": {},
           },
         },
       },
@@ -80,6 +81,9 @@ describe("applyModelDefaults", () => {
     expect(next.agents?.defaults?.models?.["google/gemini-3-flash-preview"]?.alias).toBe(
       "gemini-flash",
     );
+    expect(next.agents?.defaults?.models?.["google/gemini-3.1-flash-lite-preview"]?.alias).toBe(
+      "gemini-flash-lite",
+    );
   });
 
   it("fills missing model provider defaults", () => {