build(check): the checks compare the generated code, as CI did alone

On 23 Oct a push went red in CI because an endpoint's changed comment
hadn't been generated into the module's client: only CI compared the
committed generated code with the generator's output. tool/check.dart now
runs every server's generation (Melos' `generate`, about 15 s) after
fetching the packages and fails, naming the files, where the working
tree's generated code changed by it; the files stay written anew, to be
committed. It compares the files that differ from the committed ones
before and after by their content, so uncommitted changes count as they
do everywhere else in the checks.

It refuses a Serverpod CLI at another version than the lock holds
Serverpod at (`dart install serverpod_cli@<version>`), and the root's
tests hold CI's SERVERPOD_VERSION to the lock. CI keeps installing the
CLI at that version and puts it on the job's PATH; its own comparison
step goes, as the checks run it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

.forgejo/workflows/ci.yaml

@@ -25,7 +25,8 @@ jobs:
       # The Flutter the app is developed with; move it together with the local one.
       FLUTTER_VERSION: 3.47.5
       # The Serverpod CLI, for the generated-code check: the servers' Serverpod version
-      # (every package pins it); move it together with them.
+      # (every package pins it; the root's tests hold it to the lock); move it together
+      # with them.
       SERVERPOD_VERSION: 4.0.4
     steps:
       # Before anything else runs, the job proves it can neither see nor reach production
@@ -107,23 +108,18 @@ jobs:
         if: env.CHECKED_BEFORE != 'true'
         run: flutter pub get --enforce-lockfile || flutter pub get --enforce-lockfile
 
-      # The generated code (each server's lib/src/generated, its client package) is
-      # committed, so it has to be exactly what the generator makes of the models and
-      # endpoints: a model changed without regenerating fails here. Every server package,
-      # the apps' and the shared module, through Melos' `generate` script.
-      - name: Generated code
+      # The Serverpod CLI at SERVERPOD_VERSION, for the checks' generated-code step
+      # (tool/check.dart): the generated code is committed, so it has to be exactly what
+      # the generator makes of the models and endpoints, and the step refuses a CLI at
+      # another version than the lock holds Serverpod at.
+      - name: Serverpod CLI
         if: env.CHECKED_BEFORE != 'true'
         run: |
           bin="${XDG_STATE_HOME:-$HOME/.local/state}/Dart/install/bin"
           if ! "$bin/serverpod" --no-analytics version 2>/dev/null | grep -qx "Serverpod version: $SERVERPOD_VERSION"; then
             dart install "serverpod_cli@$SERVERPOD_VERSION"
           fi
-          PATH="$bin:$PATH" dart run melos run generate
-          if [ -n "$(git status --porcelain)" ]; then
-            git status --short
-            echo 'The generated code differs from what the generator makes now: run `serverpod generate` and commit.' >&2
-            exit 1
-          fi
+          echo "$bin" >> "$FORGEJO_PATH"
 
       # The test run mode's passwords, which passwords.yaml holds on a developer's machine
       # and which is never committed. Without them the server tests stop without a word.