Fix the Jekyll CI workflows

[jowens]

Two complementary bugs in the Jekyll workflows: the workflow that builds the site correctly can't run on branches without failing, and the one that does run on branches doesn't build the site correctly.

Noticed while opening #48 and #49, which both show a red deploy X that has nothing to do with their contents.

1. The deploy workflow runs where it cannot succeed

jekyll.yml triggered on every push with no branch filter:

on:
  push:
  workflow_dispatch:

GitHub Pages only accepts deployments from the configured source branch, so deploy fails on every feature branch. The history is unambiguous:

branch	result
mobile-demo-followups	failure
mobile-docs	failure
main × 13	success

It also parked those runs in the shared concurrency: group: "pages", where they can queue against a real main deploy.

Now restricted to main.

2. The branch check builds the wrong thing

main.yml ("Test Jekyll Build") ran:

bundle exec jekyll build --source docs --baseurl "/gridwise"

That is not how the site is assembled. _config.yml treats the repo root as the source and only points layouts_dir/includes_dir into docs/. Building from docs/ skips the root-level assets/ directory entirely:

	assets/css/style.css emitted	pages link to it
root build (deploy workflow)	✅ 12286 bytes	/gridwise/assets/css/style.css
--source docs (this check)	❌ never emitted	/gridwise/assets/css/style.css

So the check green-lit a site whose stylesheet does not exist, and could not catch a broken one. Verified by appending a deliberate syntax error to style.scss:

bundle exec jekyll build --source docs   -> exit 0   (passed)
bundle exec jekyll build                 -> exit 1   (failed)

This matters right now: #48 consists entirely of changes to assets/css/style.scss. Its green tick from this workflow proved nothing about them. The only thing that actually validated that PR was the build job inside jekyll.yml — the job whose sibling deploy produces the red X. So fixing bug 1 alone would have removed #48's only real coverage; the two changes have to land together.

3. Two smaller items

• Ruby drift: this check pinned 3.2 while deploy pins 3.3. Now both 3.3, so the PR check runs against the Ruby the published site is built with.
• Duplicate runs: it triggered on both push and pull_request, so a same-repo PR branch built twice per commit. Now pull_request plus push on main.

Verification

Both files parse as valid YAML with the intended triggers. The new build command emits style.css (12286 bytes) and exits 0 on a healthy tree, and exits 1 with a broken stylesheet — i.e. the check now fails when it should, which it previously did not.

Suggested merge order

This one first, then #48 and #49 — that way both of those get a Jekyll check that actually compiles the stylesheet, and stop showing a spurious failure.

🤖 Generated with Claude Code