ci: fix the node 20 warning and pin the protoc plugins (#84)

* ci: replace the archived buf-setup-action with buf-action

buf-setup-action is archived and runs on node20, which the runners now
warn about. buf-action is its supported replacement and runs on node24.
setup_only keeps it an install, since buf lint is its own step.

* ci: bump bun to 1.3.14

* ci: bump setup-chrome to v2.2.0

* ci: move to node 24 and drop the npm oidc workaround

node 22 is in maintenance and ships npm 10, which is why the publish job
had to install npm@latest over it. node 24 is the active lts and bundles
npm 11.17.0, above the 11.5.1 oidc floor, so the extra step goes.

* ci: pin the protoc plugins instead of installing @latest

these generate the committed stubs, so @latest makes codegen depend on
whatever released most recently. pinned to the versions proto/ records:
protoc-gen-go v1.36.11, protoc-gen-go-grpc v1.6.0.

* ci: run the ios leg on macos-26, pinned to a device and a runtime

macos-26 carries no iPhone 16 Pro at all, and on macos-15 that name spanned
iOS 18.5 through 26.2, so the leg could boot a two-major-old runtime. the
pair is now iPhone 17 Pro on iOS 26.2, resolved to a udid before boot, and
an image that drops it fails naming what it does carry.

iPhone 17 Pro is what examples/folio/justfile already defaulted to.

* ci: keep IOS_DEVICE a device name, not the resolved udid

the boot step exported the udid as IOS_DEVICE, and just ios spends that as
xcodebuild's -destination name=, which matches the display name and
rejected it: 'unable to find a device matching { name:6F69910C-... }'.

nothing downstream needed it. install, launch and terminate all address
booted, and sanderling resolves --ios-device against booted simulators
first, so the simulator this step boots is the one they all get.

.github/actions/headless-chrome/action.yml

@@ -8,7 +8,7 @@ runs:
     # the action cannot move the browser these jobs drive. The alternative it
     # offers is Chrome for Testing latest, which tracks ahead of the channel
     # users run.
-    - uses: browser-actions/setup-chrome@2e1d749697dd1612b833dba4a722266286fbefcd # v2.1.2
+    - uses: browser-actions/setup-chrome@48ad923757ca74d66703209fe939badbdf80f2f4 # v2.2.0
       with:
         chrome-version: stable