fix: clean up Gemini CLI backend checks

src/agents/cli-backends.test.ts

@@ -1026,6 +1026,7 @@ describe("resolveCliBackendConfig google-gemini-cli defaults", () => {
         defaults: {
           cliBackends: {
             "google-gemini-cli": {
+              command: "gemini",
               args: ["--skip-trust", "--output-format", "json", "--prompt", "{prompt}"],
               resumeArgs: [
                 "--skip-trust",
@@ -1061,6 +1062,7 @@ describe("resolveCliBackendConfig google-gemini-cli defaults", () => {
         defaults: {
           cliBackends: {
             "google-gemini-cli": {
+              command: "gemini",
               args: ["--skip-trust", "-o", "stream-json", "--prompt", "{prompt}"],
               resumeArgs: [
                 "--skip-trust",

src/agents/cli-runner/execute.ts

@@ -693,8 +693,8 @@ export async function executePreparedCliRun(
             delete next[key];
           }
           const backendEnv = {
-            ...(backend.env ?? {}),
-            ...(context.preparedBackend.env ?? {}),
+            ...backend.env,
+            ...context.preparedBackend.env,
           };
           if (Object.keys(backendEnv).length > 0) {
             Object.assign(
@@ -1380,7 +1380,7 @@ export async function executePreparedCliRun(
           runOutput = {
             ...parsed,
             diagnostics: {
-              ...(parsed.diagnostics ?? {}),
+              ...parsed.diagnostics,
               process: processDiagnostics,
             },
             rawText,