fix(toc): expose tableOfContents on globalThis

[JohnMcLear]

Problem

postAceInit.js fails on pad load in Chromium with:

Uncaught (in promise) ReferenceError: tableOfContents is not defined

The error blocks subsequent pad initialization. Firefox swallows it as an unhandled promise rejection, so the bug went undetected there — which is why it shipped without CI catching it.

Root cause

static/js/toc.js declares const tableOfContents = {...} at the top level of a regular <script> tag. Top-level const is script-scoped, not a global — it's not attached to window.

postAceInit.js and aceEditEvent.js are loaded by Etherpad's plugin framework as CommonJS-style modules in their own scopes, so their bare tableOfContents identifier resolves via the scope chain up to globalThis — which never had the object attached.

Fix

One-line change: assign to globalThis.tableOfContents alongside the const declaration. globalThis resolves to window in the browser and to global in Node.js, so the unit tests under tests/ (which evaluate toc.js inside a Node vm.runInNewContext) keep working — using window instead would have broken them.

Test plan

• npm test passes locally (6/6)
• npm run lint — no new errors in static/js/toc.js
• Verified in live Chromium by loading a pad with this plugin enabled — no `ReferenceError`, TOC button works.

🤖 Generated with Claude Code

[JohnMcLear]

/review