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+# Overlay editor
+
+The Overlays view edits HTML, CSS, and JavaScript independently. Each source
+tab shows line numbers and a small completion picker containing literal starter
+snippets. Selecting a completion only inserts text into the active draft; it
+does not execute or evaluate the snippet in the client.
+
+Draft changes are cached locally and autosaved to the server after the debounce
+period. The live preview uses a sandboxed iframe. Publishing is a separate
+explicit action that changes the OBS browser-source output; saving a draft does
+not publish it. Diagnostics remain available through the warning indicator,
+and the server applies the authoritative size, slug, and browser-source
+security checks.