Load same-basename Elisp companions through the generic preview runner. Demonstrate size semantics and native help, pointer, hover and keymap behavior with isolated example state.
Update Flex and Grid examples and extend reusable comparison and interaction evaluators with publication, allocation and fresh-render parity checks.
Validation: make check passed, including all 72 Playground tests.
Keep the runner generic, evaluate executable property expressions with ETAF-compatible quote semantics, and add the complete Grid reference beside the migrated Basic, Comprehensive, Flex, and Responsive fixtures.
Move the maintained gallery into a readable .ebox fixture and make ebox-playground own generic parsing, file mode, and public rendering. Keep the startup mode trigger deferred through the user's use-package configuration.
Verified with ebox-playground make check (6/6), etaf-playground make check (6/6), exact use-package startup harness, and fullscreen GUI capture at /tmp/ebox-playground-dsl-gallery.png.
Replace the bare fixture with a 720 px three-section Grid and Flex reference, add paired design documentation, and lock the compact-window width contract.\n\nVerified with make check and a single-window GUI capture at a 784 px body width; rendered content stayed at 720 px.