fix: leave terminal default foreground for uncolored text

ops.ts

@@ -202,14 +202,18 @@ export function pack(
       case OP_TEXT: {
         view.setUint32(o, OP_TEXT, true);
         o += 4;
-        view.setUint32(o, op.color ?? 0xFFFFFFFF, true);
+        // No explicit color: leave the terminal default foreground by writing
+        // 0 and setting ATTR_DEFAULT (0x80 in the attrs byte). The C path ORs
+        // it into fg and emit_attr skips the foreground SGR (mirrors unset bg).
+        let textDefault = op.color === undefined;
+        view.setUint32(o, op.color ?? 0, true);
         o += 4;
         view.setUint32(
           o,
           (op.fontSize ?? 1) |
             ((op.fontId ?? 0) << 8) |
             ((op.wrap ?? 0) << 16) |
-            ((op.attrs ?? 0) << 24),
+            (((op.attrs ?? 0) | (textDefault ? 0x80 : 0)) << 24),
           true,
         );
         o += 4;

test/default-foreground.test.ts

@@ -0,0 +1,15 @@
+import { text } from "../ops.ts";
+import { createTerm } from "../term.ts";
+import { describe, expect, it } from "./suite.ts";
+
+const decode = (b: Uint8Array) => new TextDecoder().decode(b);
+
+describe("true default foreground", () => {
+  it("emits uncolored text with no concrete foreground", async () => {
+    let term = await createTerm({ width: 12, height: 1 });
+    let ansi = decode(term.render([text("hi")]).output);
+
+    expect(ansi).toContain("hi");
+    expect(ansi).not.toContain("\x1b[38;2;255;255;255");
+  });
+});