fix(agent): prevented consuming legacy steering queue during mid-batch interrupts

- Stopped calling the consuming `getSteeringMessages` getter during mid-batch interrupt polls to prevent stranding or dropping messages before they reach the injection boundary.
- Skip subsequent steering checks in the poll loop once an interrupt has already triggered.
- Added a regression test to ensure legacy steering remains queued until the injection boundary when no non-consuming peek exists.

packages/coding-agent/test/bash-executor.test.ts

@@ -137,7 +137,6 @@ describe("executeBash", () => {
 		expect(result.output.trim()).toBe(tempDir);
 	});
 
-
 	it("honors symlinked cwd requests in persistent shells", async () => {
 		if (process.platform === "win32") {
 			return;