The upcoming events table pulled its ICS parser straight from a CDN with
`import ICAL from "https://unpkg.com/ical.js/dist/ical.min.js"`. That sends
every visitor of the start page to unpkg.com, which hands their IP address and
user agent to a third party before any of our own code runs. The URL is not
even pinned to a version, so whatever ical.js publishes next is executed on our
site without anybody looking at it, and the start page silently breaks when the
CDN is unreachable.
Check the parser into `assets/js/vendor/` and let Hugo bundle it. This is what
`js.Build` is for: it runs the esbuild that is built into Hugo, so it resolves
the import at build time and needs no node_modules and no extra tooling in the
build environment. The result is minified and fingerprinted like the other
scripts of the site, and the script tag carries a subresource integrity hash.
Since the bundle now has a content hash in its name, its URL cannot be written
by hand in the markdown any more. Move the table and the script tag into an
`upcoming` shortcode, which is the same pattern `calendar.html` already uses,
and move `upcoming.js` from `static/` to `assets/` so Hugo can process it.
The vendored file is the unminified `dist/ical.js` of the pinned release: it
carries the MPL-2.0 header and is the source form of what we ship, and Hugo
minifies it for delivery anyway. `assets/js/vendor/README.md` records the
version, where it came from and how to update it.
The built bundle renders the same table as before, checked against
https://berlin.ccc.de/calendars/all.ics.
Fixes: c28f04c6e8 ("switch to ics files; make calendars work; fix some minor issues")
Assisted-by: Claude:claude-opus-5
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
