test(ha-config-bootstrap): RED phase tests for quorum election logic (task 4.1)

- 21 test functions covering all 12 acceptance criteria (req 2.1-2.12)
- Tests: 2/3 quorum wins, 1/3 loses, voted_for enforcement, freshness gate,
  single-node self-elects, split-vote retry, in_catch_up denial, jitter
- Build fails with undefined reference to handle_request_vote,
  ha_elect_evaluate_and_signal, am_i_primary_quorum (expected RED proof)

src/controller/meson.build

@@ -102,6 +102,7 @@ controller_unit_test_src = [
   'testsuite/test_config_repl.c',
   'testsuite/test_worker_join.c',
   'testsuite/test_ha_startup.c',
+  'testsuite/test_ha_election.c',
   'startup_validation.c',
   'worker.c',
   'persist.c',