refactor(monkeyd): port the crawler in-tree and drop the submodule

The monkeyd-crawler repository moved into tiennm99/mttools, so recursive
clones of the old submodule URL fail and block every deploy. The crawler,
PDF renderer, and export flow now live under internal/modules/monkeyd,
trimmed to the bot's use: a fixed phone page, the bundled font only, and
the font size as the single export option.

internal/modules/monkeyd/export/export_test.go

@@ -0,0 +1,81 @@
+package export
+
+import "testing"
+
+func TestValidate(t *testing.T) {
+	tests := []struct {
+		name    string
+		req     Request
+		wantErr bool
+	}{
+		{
+			name: "url and font size are valid",
+			req:  Request{NovelURL: "https://monkeydd.com/example.html", FontSize: DefaultFontSize},
+		},
+		{
+			name:    "missing url",
+			req:     Request{FontSize: DefaultFontSize},
+			wantErr: true,
+		},
+		{
+			name:    "non-http scheme",
+			req:     Request{NovelURL: "ftp://monkeydd.com/example.html", FontSize: DefaultFontSize},
+			wantErr: true,
+		},
+		{
+			name:    "scheme-less url",
+			req:     Request{NovelURL: "monkeydd.com/example.html", FontSize: DefaultFontSize},
+			wantErr: true,
+		},
+		{
+			name:    "negative font size",
+			req:     Request{NovelURL: "https://monkeydd.com/example.html", FontSize: -1},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.req.validate()
+			if tt.wantErr && err == nil {
+				t.Error("validate() = nil, want error")
+			}
+			if !tt.wantErr && err != nil {
+				t.Errorf("validate() = %v, want nil", err)
+			}
+		})
+	}
+}
+
+// An invalid request must fail before the crawler makes any request.
+func TestExportRejectsInvalidRequestWithoutFetching(t *testing.T) {
+	if _, err := Export(t.Context(), Request{NovelURL: "ftp://monkeydd.com/x.html", OutDir: t.TempDir()}); err == nil {
+		t.Fatal("Export = nil error, want an invalid url error")
+	}
+}
+
+func TestSafeFileName(t *testing.T) {
+	tests := []struct {
+		title    string
+		fallback string
+		want     string
+	}{
+		{"Trở Lại Năm Tháng Cũ", "slug", "Trở-Lại-Năm-Tháng-Cũ"},
+		{"Chapter: One / Two", "slug", "Chapter-One-Two"},
+		{"  ---  ", "slug", "slug"},
+		{"", "slug", "slug"},
+	}
+	for _, tt := range tests {
+		if got := SafeFileName(tt.title, tt.fallback); got != tt.want {
+			t.Errorf("SafeFileName(%q, %q) = %q, want %q", tt.title, tt.fallback, got, tt.want)
+		}
+	}
+}
+
+func TestResultSummary(t *testing.T) {
+	r := &Result{Title: "Example", Chapters: 12, Words: 3400}
+	want := "Example — 12 chapters, 3400 words"
+	if got := r.Summary(); got != want {
+		t.Errorf("Summary() = %q, want %q", got, want)
+	}
+}