go/asks: an ask says what a channel that proves who answers shows whole, and what Details shows (hq issue 383)

A settings proposal reached the phone with its values masked, so the operator could not
tell what they were approving. An ask now carries Whole, shown in place of Explanation on
a kind that proves its sender and carries the ask's answers, and Details, what the
Details answer shows. Both enter the digest only when given, so an ask without them
digests as before and a router and an asker of different builds still agree on it.

go/asks/asks_test.go

@@ -230,9 +230,31 @@ func TestDigestsAreCanonicalOverNamedFields(t *testing.T) {
 			t.Errorf("changing %s left the digest the same", name)
 		}
 	}
+	// Whole and Details (issue 383) are in the digest once given, and change it; an ask without either digests
+	// exactly as before they existed — the encoding by hand, so no build can drift from it unseen.
+	plain := Ask{ID: "p", Headline: "h", Explanation: "e", Who: Operator, Expires: now, OnExpiry: "o", About: "a",
+		Options: []Option{{ID: "ok", Label: "OK", Does: "d", Level: Acknowledge}}}
+	byHand := sha256.Sum256([]byte("novox.ask.v1\n1:p\n1:h\n1:e\n8:operator\n20:2026-10-08T14:00:00Z\n1:o\n1:a\n5:false\n1:1\n" +
+		"2:ok\n2:OK\n1:d\n11:acknowledge\n0:\n"))
+	if plain.Digest() != "sha256:"+hex.EncodeToString(byHand[:]) {
+		t.Errorf("an ask without Whole and Details does not digest as it did before them: %s", plain.Digest())
+	}
+	withWhole, withDetails := plain, plain
+	withWhole.Whole = "e, whole"
+	withDetails.Details = "fingerprint 1234"
+	if withWhole.Digest() == plain.Digest() || withDetails.Digest() == plain.Digest() || withWhole.Digest() == withDetails.Digest() {
+		t.Error("Whole or Details left the digest the same")
+	}
+	both := withWhole
+	both.Details = "fingerprint 1234"
+	changed := both
+	changed.Whole += "!"
+	if changed.Digest() == both.Digest() {
+		t.Error("changing Whole beside Details left the digest the same")
+	}
 	// A field added to Ask or Option without being added to Digest fails here.
-	if n := reflect.TypeOf(Ask{}).NumField(); n != 9 {
-		t.Errorf("Ask has %d fields, and Digest covers 9: add the new one to Digest and to this test", n)
+	if n := reflect.TypeOf(Ask{}).NumField(); n != 11 {
+		t.Errorf("Ask has %d fields, and Digest covers 11: add the new one to Digest and to this test", n)
 	}
 	if n := reflect.TypeOf(Option{}).NumField(); n != 5 {
 		t.Errorf("Option has %d fields, and Digest covers 5: add the new one to Digest and to this test", n)