CTR optimization, sitemap lastmod, internal links to landing pages

1. Title: "XSLT Tester & Validator Online — Free, XSLT 1.0/2.0/3.0"
   Description: leads with "Run, test and validate" action verbs.
   Targets low-CTR queries: xslt tester, xsl validator (pos 6-8, CTR <1%).

2. Sitemap: add lastmod 2026-05-26 to all entries to signal freshness
   and accelerate Googlebot crawl of /xslt-2-0/ and /xslt-3-0/
   (both 0 impressions — never crawled despite being live for 3 weeks).

3. Blog internal links: update 3 posts to link directly to
   /xslt-2-0/ and /xslt-3-0/ landing pages instead of root,
   giving Googlebot anchor text and link equity for those URLs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

site/content/posts/xslt-3-new-features.md

@@ -92,6 +92,6 @@ Packages reduce coupling and enable reuse across projects without copy-paste.
 
 ## Try it in XSLT Playground
 
-All the examples above run in [XSLT Playground](https://xsltplayground.com) with version set to 3.0. Maps and JSON support are the quickest to explore. Paste the `json-to-xml()` example, provide a JSON string as input, and see the intermediate representation immediately.
+All the examples above run in the [XSLT 3.0 Online Tester](https://xsltplayground.com/xslt-3-0/) — Saxon 12 included, no install. Maps and JSON support are the quickest to explore. Paste the `json-to-xml()` example, provide a JSON string as input, and see the intermediate representation immediately.
 
 XSLT 3.0 is available today. If your integration still targets 2.0, the features above are the best reasons to upgrade.

site/content/posts/xslt-debugging-patterns.md

@@ -30,4 +30,4 @@ You can drop this at the top of the stylesheet, run a quick transform, and then
 
 Finally, keep a checklist of the classic XSLT footguns: missing namespaces, wrong context node, incorrect `@` in attribute selection, and predicates that use 1-based indexes when you thought they were 0-based. I also look for template import precedence issues and for unexpected whitespace handling when the output is textual. These are easy to miss because the transform still runs, it just runs incorrectly.
 
-If you want a fast place to test these patterns with real inputs, use the online editor at [https://xsltplayground.com](https://xsltplayground.com). It is built for rapid iteration with multiple inputs and parameters, which makes debugging much less painful and keeps your feedback loop tight.
+If you want a fast place to test these patterns with real inputs, use the [XSLT online editor at xsltplayground.com](https://xsltplayground.com). It supports [XSLT 2.0](https://xsltplayground.com/xslt-2-0/) and [XSLT 3.0](https://xsltplayground.com/xslt-3-0/) via Saxon, and is built for rapid iteration with multiple inputs and parameters.

site/content/posts/xslt-grouping-for-each-group.md

@@ -132,4 +132,4 @@ These group nodes based on a pattern match rather than a key value. Every time a
 
 ## Try it in XSLT Playground
 
-Paste any of the examples above into [XSLT Playground](https://xsltplayground.com) with version set to 2.0 or 3.0. Grouping is one of the features that benefits most from live testing — you can immediately see how changing the grouping key or switching between `group-by` and `group-adjacent` affects the output structure.
+Paste any of the examples above into the [XSLT 2.0 Online Tester](https://xsltplayground.com/xslt-2-0/) — Saxon HE included, no install. Grouping is one of the features that benefits most from live testing — you can immediately see how changing the grouping key or switching between `group-by` and `group-adjacent` affects the output structure. For `xsl:stream`, switch to the [XSLT 3.0 tester](https://xsltplayground.com/xslt-3-0/).