Include aggregate doc/install goals in scoping filter

Per @chatgpt-codex-connector review on #4: docs is also reached via
\`make docs\` (which routes to srcs-doc + \$(DOCTARGETS)) and via
\`make install INSTALLDOC=all\` (do-install-all has docs in its prereqs).
In those cases MAKECMDGOALS only contains \`docs\` or \`install\`/
\`install-all\`/\`reinstall\`, so the previous filter stayed false and
the ordering between prepare-gems and ext/configure-ext.mk regen was
not enforced -- a clean-tree parallel docs install could still race.

Add \`docs install install-all install-doc install-html install-rdoc
reinstall\` to the filter. For \`make install INSTALLDOC=nodoc\`,
prepare-gems was already pulled in transitively via pre-install-gem,
so this only adds an ordering constraint, not a new fetch.

Verified with \`make -n\` on a clean tree: plain \`make\` does not
extract gems; \`make docs\`, \`make install\`, and \`make html\` do.

https://claude.ai/code/session_01YRoRyZPew2LtN6u6BX8bzx

Author: claude

defs/gmake.mk

@@ -369,7 +369,7 @@ extract-gems: | $(call foreach-bundled-gems-rev,bundled-gem-extracted)
 # prepare-gems may not have run yet, so make the dep explicit for the
 # docs goals. Other targets are left alone so a plain `make` doesn't
 # reach for prepare-gems -> update-gems (network).
-ifneq ($(filter rdoc rdoc:% html html-server rdoc-coverage undocumented,$(MAKECMDGOALS)),)
+ifneq ($(filter rdoc rdoc:% html html-server rdoc-coverage undocumented docs install install-all install-doc install-html install-rdoc reinstall,$(MAKECMDGOALS)),)
 ext/configure-ext.mk: $(HAVE_BASERUBY:yes=prepare-gems)
 endif