Bind standalone fixture renders to the compact playground viewport, paint reference spacers across the canvas, and give every tinted content box explicit high-contrast ink. Add regression coverage for width, painted separators, and fixture color contracts.
Show the Ebox DSL render shortcut in the source header line and route C-c C-c through the public display API so the generated preview is automatically shown.
Verification: make check EMACS=/Applications/Emacs.app/Contents/MacOS/Emacs; GUI daemon key-path smoke test with clean source and preview screenshots.
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.
