ci: regenerate example trees in the weekly bundled-update workflow

After re-blessing the golden snapshots, replay each example tree's
recorded command against the refreshed bundle (`gloam regen --fresh`;
locked regen would refuse pins the new bundle no longer satisfies) and
include examples/ in the PR.

Regenerated files embed gloam's own version/commit, so a regen at a new
HEAD always produces cosmetic churn; the regen is kept only when the diff
is significant under the same filter `gloam regen` prints for human
review (preamble stamps, the manifest's gloam meta block, and the output
BOM's file hashes).  A real change always registers: generated-file
content shows its own diff, and a provenance pin advance moves the
unfiltered 6-space "commit" line — so a no-op bundle refresh leaves the
PR without example churn, while both spec-driven and generator-driven
output changes are committed alongside the bundle they came from.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>

Author: tycho

.github/workflows/update-bundled.yml

@@ -47,6 +47,32 @@ jobs:
       - name: Run test suite against updated files
         run: cargo test --release --no-default-features
 
+      - name: Regenerate example loader trees
+        # Replays each tree's recorded command against the refreshed bundle
+        # (`--fresh`: locked regen would refuse pins the new bundle no longer
+        # satisfies).  Regenerated files embed gloam's own version/commit, so
+        # a regen at a new HEAD always produces cosmetic churn; the regen is
+        # kept only when something beyond those stamp lines changed.  The
+        # filter mirrors the one `gloam regen` prints for human review:
+        # preamble stamps, the manifest's gloam meta block, and the output
+        # BOM's file hashes (which track stamp changes byte-for-byte).  A
+        # real source change always stays visible — a provenance pin's blob
+        # never moves without its unfiltered sibling "commit" line moving
+        # too.  `git add -N` makes any newly emitted file visible to the
+        # diff before it is judged.
+        run: |
+          set -euo pipefail
+          cargo run --release --no-default-features -p gloam -- regen --fresh examples
+          git add -N examples
+          if git diff -I'^ \* @generated by gloam ' -I'^// @generated by gloam ' \
+                      -I'^    "(version|describe|commit)": ' -I'^      "blob": ' \
+                      --quiet -- examples; then
+            echo "Examples unchanged beyond gloam version/commit stamps; reverting."
+            git reset -q -- examples
+            git checkout -- examples
+            git clean -qfd examples
+          fi
+
       # Build a human-readable provenance summary (one line per upstream repo,
       # with its git describe) for the PR body, straight from the manifest the
       # bundler just wrote.
@@ -72,6 +98,7 @@ jobs:
           add-paths: |
             bundled/
             tests/golden/
+            examples/
           commit-message: |
             chore: update bundled specs, headers, and provenance
 
@@ -97,6 +124,11 @@ jobs:
             moved.  Any diff under `tests/golden/` shows exactly how the new
             specs change generated loader output; no golden diff means the
             update is output-neutral for the snapshot configs.
+
+            The example loader trees under `examples/` were regenerated
+            against the new bundle (`gloam regen --fresh`); they appear in
+            this PR only if the update changed them beyond gloam's own
+            version/commit stamp lines.
           branch: update-bundled-xml
           delete-branch: true
           labels: dependencies