ci: run the new suites, and check tag/version agreement at release time

These were split out of #428/#429 because the token pushing them lacked the
`workflow` scope. Folding them in here rather than opening a stacked PR --
#429 was merged into its stacked base after that base had already been
squash-merged, so its content never reached main, and one such near-miss is
enough.

All three enrolled suites exist on this branch: test_version_consistency.py
came with #428 and is on main; the other two arrive with the commits above.
Enrolling them in a separate PR would have either raced with this one on
test.yml or briefly pointed CI at files main did not have.

- test.yml: enroll test_version_consistency, test_plugin_compatibility_gate
  and test_install_preserves_existing in the core unit job. Until now these
  32 tests existed but nothing ran them automatically.

- release-version-check.yml: run scripts/check_release_version.py on pushed
  v* tags and published releases, plus workflow_dispatch so a tag can be
  checked *before* it is created. No dependencies -- it reads src/__init__.py
  and CHANGELOG.md only.

Verified: both workflow files parse, and the release check still passes for
v3.2.0 against this tree.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Udr6MfaFLUPhX5Fgo67Jf5

.github/workflows/test.yml

@@ -76,4 +76,7 @@ jobs:
             test/test_sports_core_promotions.py \
             test/test_sports_modes_promotions.py \
             test/test_sports_capabilities.py \
-            test/test_sports_scroll.py
+            test/test_sports_scroll.py \
+            test/test_version_consistency.py \
+            test/test_plugin_compatibility_gate.py \
+            test/test_install_preserves_existing.py