feat(parse): apply watermark_handling to text output; add watermark e2e test (#27932)

Stainless-Generated-From: 539f4b3933a49763b3c254124d3071caba85a38e

Author: stlc-bot

pkg/cmd/parsing.go

@@ -227,7 +227,7 @@ var parsingCreate = requestflag.WithInnerFlags(cli.Command{
 		},
 		&requestflag.InnerFlag[*string]{
 			Name:       "output-options.watermark-handling",
-			Usage:      "What to do with watermark text stamped across the page (e.g., 'CONFIDENTIAL', 'DRAFT'): 'move_to_end' (default) keeps it as the last block of the page's markdown and text output, 'move_to_start' as the first block, and 'remove' drops it. In every mode the detected text is reported in the page's `watermark` metadata. Requires version 2026-09-28 or later on the cost_effective, agentic, and agentic_plus tiers; ignored otherwise",
+			Usage:      "What to do with watermark text stamped across the page (e.g., 'CONFIDENTIAL', 'DRAFT'): 'move_to_end' (default) keeps it as the last block of the page's markdown, 'move_to_start' as the first block, and 'remove' drops it. The text output follows the same choice where the watermark is a line of its own in the PDF text layer. In every mode the detected text is reported in the page's `watermark` metadata. Requires version 2026-09-28 or later on the cost_effective, agentic, and agentic_plus tiers; ignored otherwise",
 			InnerField: "watermark_handling",
 		},
 	},