feat(ha-heartbeat-liveness): add last_activity and last_push_time state fields (task 1.1)

Add time_t last_activity to ha_state_t for standby liveness timestamp tracking.
Add time_t last_push_time to standby_ep_ctx_t for primary idle NOP suppression.
Zero-initialize last_activity in ha_init(); last_push_time zeroed by calloc.
Add test_ha_init_last_activity_is_zero to test_ha_startup.c.

src/controller/ha.c

@@ -656,6 +656,10 @@ int ha_init(ha_state_t *ha, const ha_config_t *cfg, int my_priority)
     ha->n_peers         = 0;
     atomic_store_explicit(&ha->repl_ack_count, 0, memory_order_relaxed);
 
+    /* ha-heartbeat-liveness Task 1.1: zero-init liveness timestamp.
+     * Written by ha_on_heartbeat_received (task 2.1); read by liveness_poll_fn. */
+    ha->last_activity = 0;
+
     /* heartbeat_seen starts at 0: no heartbeat seen yet.
      * ha_wait_for_heartbeat_or_timeout() calls sem_timedwait on this. */
     sem_init(&ha->heartbeat_seen, 0, 0);
@@ -2856,8 +2860,12 @@ void ha_disarm_heartbeat_timeout_vtask(ha_state_t *ha)
 typedef struct {
     ha_state_t     *ha;
     cluster_t      *c;
-    ha_elect_ctx_t *ctx;       /* always NULL — not a vote endpoint */
-    int             peer_idx;  /* index into c->myconf->peers_cfg.candidates[] */
+    ha_elect_ctx_t *ctx;        /* always NULL — not a vote endpoint */
+    int             peer_idx;   /* index into c->myconf->peers_cfg.candidates[] */
+    /* Task 1.1 (ha-heartbeat-liveness): last time a push/nop was sent to this
+     * standby (CLOCK_MONOTONIC seconds).  Initialized to 0 at allocation;
+     * written by on_standby_connected and primary_heartbeat_fn (task 2.2). */
+    time_t          last_push_time;
 } standby_ep_ctx_t;
 
 /*
@@ -2907,6 +2915,11 @@ static void on_standby_connected(endpoint_t *ep)
         INFO("HA: outbound standby connection to peer[%d] established, ctrlhello sent",
              sctx->peer_idx);
 
+    /* Send an immediate NOP so the standby's heartbeat watchdog deadline resets
+     * now rather than waiting up to heartbeat_interval_ms for the first periodic
+     * heartbeat — avoids a false timeout when committing_timeout_ms ≈ heartbeat_timeout_ms. */
+    xce_nop_req(ep);
+
     /* Set state-aware dispatcher for subsequent messages on this endpoint */
     ep->msg_handler = peer_ctrl_msg_handler;
 }

src/controller/ha.h

@@ -183,6 +183,8 @@ typedef struct {
     /* ── New fields added by raft-library spec (Task 6.2) ──────── */
     cluster_t       *raft_c;           /* cluster_t* set by ha_start_election_async; used by raft callbacks */
     void            *raft_election_timeout_ctx; /* election_timeout_ctx_t* for cancel (task 6.2) */
+    /* ── New fields added by ha-heartbeat-liveness spec (Task 1.1) ── */
+    time_t           last_activity;    /* CLOCK_MONOTONIC seconds of last primary message; 0 = none yet */
 } ha_state_t;
 
 /* ── Public API ────────────────────────────────────────────── */

src/controller/testsuite/test_ha_startup.c

@@ -589,6 +589,24 @@ static void test_dispatch_gate_committing_allows_repl_ops(void)
     printf("test_dispatch_gate_committing_allows_repl_ops: PASS\n");
 }
 
+/* ── Task 1.1 (ha-heartbeat-liveness): ha_init() zero-initializes last_activity ─
+ *
+ * Req 1.1, 1.3, 3.1: ha_state_t must carry a `time_t last_activity` field that
+ * is zero-initialized by ha_init().  Later tasks (2.1) write to this field via
+ * ha_on_heartbeat_received(); task 3.1 reads it for liveness polling.
+ */
+static void test_ha_init_last_activity_is_zero(void)
+{
+    ha_state_t ha;
+    ha_init(&ha, &g_dispatch_cfg, 0);
+
+    TEST_ASSERT_EQUAL_INT_MESSAGE(0, (int)ha.last_activity,
+        "ha_init must zero-initialize last_activity (liveness field)");
+
+    ha_fini(&ha);
+    printf("test_ha_init_last_activity_is_zero: PASS\n");
+}
+
 /* ── Task 5.1: myapp_run startup sequence ────────────────────────────────
  *
  * Req 1.1, 9.3, 9.4: myapp_run must call ha_start_election_async (non-blocking)
@@ -744,4 +762,7 @@ void test_ha_startup(void)
     RUN_TEST(test_nonblocking_single_node_election_sets_n_peers);
     RUN_TEST(test_nonblocking_single_node_election_enters_committing);
     RUN_TEST(test_nonblocking_election_returns_in_under_10ms);
+
+    /* Task 1.1 (ha-heartbeat-liveness) — ha_init zero-initializes last_activity */
+    RUN_TEST(test_ha_init_last_activity_is_zero);
 }