feat(ha-single-leader-role): delete dispatch-gate COMMITTING branch + collapse role predicates to PRIMARY (task 4.2)

.kiro/specs/ha-single-leader-role/tasks.md

@@ -45,7 +45,7 @@
   - Observable completion: controller builds; `grep -rn "committing_timeout_fn\|ha_check_majority_convergence\|ha_repl_ack_received" src/controller/*.c src/controller/*.h` returns zero matches; test suite green
   - _Requirements: 1.5, 2.3_
 
-- [ ] 4.2 Delete the dispatch-gate COMMITTING branch and collapse role predicates
+- [x] 4.2 Delete the dispatch-gate COMMITTING branch and collapse role predicates
   - Delete ONLY the `case CTRL_PRIMARY_COMMITTING:` block from `ha_dispatch_gate` (ha.c:1594-1612 pre-rollout anchor — re-grep; the block follows the ELECTING case); the CTRL_PRIMARY branch — including barrier-rollout's no-quorum fact allowlist (`OPCode_notify/update/setpreason/clrpreason`) — is preserved byte-for-byte
   - Collapse compound role checks to PRIMARY-only: `raft_cb_vote_eligible` (ha.c:210-211), `handle_request_vote` gates (ha.c:1984, 2004), `vote_ep_err_handler` (ha.c:3159), `peer_ctrl_msg_handler` case labels (ha.c:2789), `primary_heartbeat_fn` re-arm/run condition (ha.c:3956 — heartbeat re-arm condition drops COMMITTING); update the stale comments at each site plus ha.c:1940, 1971, 2057-2060, 2625-2627, 3044-3045 and the `ha_is_primary`/`ha_should_redirect` doc comments (no code change in those two functions)
   - Update gate tests: COMMITTING-specific cases in `test_ha_vote_gate.c` and gate fixtures retargeted (elected node denies same-term votes as PRIMARY — denial parity pinned)
@@ -86,6 +86,8 @@
 - **Unity runner gotcha**: the aggregated controller runner prints the PREVIOUS passing test's `file:line` as a stale prefix on a FAIL line — attribute failures by test NAME, not the printed file:line prefix.
 - **(3.1) Legacy path routes through BARE helpers, not `ha_promote_to_primary`**: `ha_elect_evaluate_and_signal`'s PRIMARY branch calls `ha_register_persist_hooks` + `ha_start_primary_heartbeat` + `ha_arm_own_term_gate` directly (matching the raft path), NOT `ha_promote_to_primary` — because the latter calls `ha_do_promote` (term increment) and the legacy branch historically has NO term store/increment (research §4 finding 2). This is a deliberate deviation from design §283's loose wording ("route through ha_promote_to_primary / ha_register_persist_hooks"); the bare-helper route preserves term semantics and is the correct reading.
 - **(4.1) No shims — DELETE, don't stub** (design §Transitional-State Deletions / §Design Synthesis: "rewritten or DELETED, not stubbed"). Machinery-subject test cases (convergence checker, committing watchdog, ack-driven promotion, ack counting) were DELETED, not shimmed: test_ha_role.c (5 majority_convergence + 2 committing_timeout_promotes_degraded), test_ha_rdhup_integration.c (rdhup_committing_to_primary_on_ack, rdhup_3node_one_ack_promotes), test_ha_connection_reuse.c (dispatcher_committing_handles_repl_ack, promoted_ep_repl_ack_promotes_to_primary). Kept state-entry cases had their deleted-fn CALLS excised (not shimmed). `test_ha_connection_reuse.c` was overlooked by the spec's §3 census disposition for machinery cases — confirmed in census (line 97) but its ack cases needed DELETE, not UPDATE.
+- **(4.2) Residual stale COMMITTING comments in ha.c** (~lines 443, 826, 1240): documentary prose on the legacy raft_cb_become_leader/convergence path — NOT live branches. Scrub in 5.2/6.x (they fail the task-6.2 repo-wide grep). After 4.2, ZERO live code branches on `CTRL_PRIMARY_COMMITTING` in ha.c; the enum value persists in ha.h:64 until 5.2.
+- **(4.2) Test-leak / suite-timeout facts**: the controller test target sets `ASAN_OPTIONS=detect_leaks=0` (controller/meson.build:163), so a pre-existing suite-wide LSan leak (~153KB, present at baseline 678b7f8, this spec leaks slightly LESS) is suppressed under the meson gate — LSan exit=1 only on a RAW direct-binary run, not a regression. The controller suite runs ~268s against a 300s meson timeout — borderline; the final task-6.2 full regression may TIMEOUT under machine load — re-run if so (it is not a failure).
 - **(4.1) Residual for task 6.2 final grep**: 3 DOCUMENTARY PROSE comments in `test_ha_role_lifecycle.c` (~lines 760/815/825) still mention `ha_repl_ack_received`/`committing_timeout_fn` by name (no live code). The 4.1 gate (`src/controller/*.c|*.h`) excludes testsuite so this passed; the task-6.2 repo-wide grep WILL catch them — scrub these comments in 5.x/6.x. Also a non-tracked editor backup `src/controller/.ha.c.~undo-tree~` holds stale refs (irrelevant; not a build input — do not commit).
 - **(3.1) Expected-failure set after task 3.1 (8 category-(a), all owned downstream)**: task 4.1 DELETES `test_ha_evaluate_committing.c` (3 fails: test_winning_quorum_enters_committing, test_committing_resets_repl_ack_count, test_election_timeout_fn_fires_evaluate); task 5.1 retargets `test_nonblocking_single_node_election_enters_committing` (test_ha_startup.c), `test_3node_win_calls_both_pushes` (test_ha_repl_push.c), and 3 RDHUP cases (test_ha_rdhup_integration.c: rdhup_full_path_reaches_committing, rdhup_committing_to_primary_on_ack, rdhup_3node_one_ack_promotes). `committing_timeout_fn` now has a benign `-Wunused-function` warning (no arming site left) until task 4.1 deletes it.
 - **Lifecycle fixture (test_ha_role_lifecycle.c)**: `lifecycle_cluster_setup` installs `repl_broadcast_send_hook = lc_drop_send_hook` (drop-only, reset to NULL in teardown) — required once promotion broadcasts the WAL_NOOP, else fake `int` endpoints cause an ASAN overflow. Gate cases prime `current_lsn = noop_lsn` so the post-increment append lands the noop at `noop_lsn` (production derives `noop_lsn = current_lsn-1`).