phraser, mavend: read the fallbacks from the file (V-501)

The accessors are functions now, so the call sites that compared against one
literal compare against the entry instead: IsUnknownFallback and
IsSourcesFallback in the daemon tests, the entry key in the phraser tests. A
reworded variant no longer breaks a Go test.

The eval scores every variant on the persona checks the nudges already pass.

cmd/mavend/query_recall_test.go

@@ -121,8 +121,8 @@ func TestQueryRecallNoteCanWin(t *testing.T) {
 			{text: "выучил пару аккордов", score: 0.50, kind: "note"},
 		})
 		reply := askQuery(t, h, q)
-		if want := "вот что я нашла: молоко стоит в холодильнике"; reply != want {
-			t.Errorf("reply %q, want %q", reply, want)
+		if !phraser.IsSourcesFallback(reply, "молоко стоит в холодильнике") {
+			t.Errorf("reply %q, want the note read back", reply)
 		}
 		// One text, the winning memory's — the answer came from the memory
 		// pass, not from handing the phraser every note in the table.
@@ -151,7 +151,7 @@ func TestQueryRecallNoteCanWin(t *testing.T) {
 			{text: "молоко стоит в холодильнике", score: 0.860, kind: "note"},
 			{text: "молоко закончилось", score: 0.858, kind: "note"},
 		})
-		if reply := askQuery(t, h, q); reply != "не знаю." {
+		if reply := askQuery(t, h, q); !phraser.IsUnknownFallback(reply) {
 			t.Errorf("reply %q, want silence", reply)
 		}
 	})