v2.11.0

Eight new documentation completeness checkpoints (TD-43 through TD-50), covering both mechanical validation and LLM-assisted review.

TD-43 verifies that guides.xml version and release fields stay in sync with ext_emconf.php (consolidated into TD-30). TD-44 checks that all six expected documentation sections are present: Introduction, Installation, Configuration, Usage, Developer, and FAQ. TD-45 detects untranslated literal strings in Fluid templates that should use f:translate. TD-46 validates that RST substitutions defined in Includes.rst.txt are actually used. TD-47 warns about PlantUML directives that may not render on docs.typo3.org. TD-48 ensures every git tag has a corresponding CHANGELOG.md entry. TD-49 flags extensions with more than 10 classes that lack an Adr/ directory for architecture decision records. TD-50 is an LLM-review checkpoint that validates code examples in documentation against the actual API.

Also removes .serena/ from version control — it contains local project configuration that shouldn't be committed.

Full Changelog: v2.10.0...v2.11.0