fix(coding-agent): handle frontmatter prompts in print mode

closes #4163

packages/coding-agent/test/args.test.ts

@@ -43,6 +43,21 @@ describe("parseArgs", () => {
 			const result = parseArgs(["-p"]);
 			expect(result.print).toBe(true);
 		});
+
+		test("parses prompt after -p even when it starts with YAML frontmatter", () => {
+			const prompt = "---\ntitle: hello\n---\nSay hi.";
+			const result = parseArgs(["-p", prompt]);
+			expect(result.print).toBe(true);
+			expect(result.messages).toEqual([prompt]);
+			expect(result.unknownFlags.size).toBe(0);
+		});
+
+		test("does not consume options after -p as prompts", () => {
+			const result = parseArgs(["-p", "--provider", "openai", "Say hi."]);
+			expect(result.print).toBe(true);
+			expect(result.provider).toBe("openai");
+			expect(result.messages).toEqual(["Say hi."]);
+		});
 	});
 
 	describe("--continue flag", () => {