feat(monkeyd): accept an optional font size argument

/monkeyd_crawl <url> [font_size] sets the body text size in points, half points
included, bounded to 6-24. Omitting it sends no size at all so the crawler's
default applies, rather than defining a second default here that could drift.
The document caption reports the size used.

Also advance the submodule to the lower 10pt default: on the 90x160mm phone
page that fits about 43 characters per line instead of 36.

cmd/server/command_menu_test.go

@@ -67,7 +67,7 @@ func TestCommandDiscovery_AllPublicCommandsHaveSafeMetadata(t *testing.T) {
 		"gold_sell":            "<luong>",
 		"lol":                  "[date]",
 		"loldle":               "[champion]",
-		"monkeyd_crawl":        "<url>",
+		"monkeyd_crawl":        "<url> [font_size]",
 		"random":               "<option,...>",
 		"stats":                "[users | user <username> | cmd <command_name>]",
 		"stock_events":         "<ticker> [days]",