fix(pricing): support Perplexity/Vertex price format without dollar sign

- official_pricing_import_common.go: make dollar sign optional in firstDollarPrice regex
- perplexity_pricing_lib.go: fix column detection to match 'Input ($/1M)' format
- also updated vertex and perplexity baseline snapshots

scripts/official_pricing_import_common.go

@@ -362,7 +362,7 @@ func cleanHTMLText(raw string) string {
 }
 
 func firstDollarPrice(raw string) (float64, bool) {
-	pattern := regexp.MustCompile(`\$ ?([0-9]+(?:\.[0-9]+)?)`)
+	pattern := regexp.MustCompile(`\$? ?([0-9]+(?:\.[0-9]+)?)`)
 	match := pattern.FindStringSubmatch(raw)
 	if len(match) != 2 {
 		return 0, false