fix(ha): fix config replication to standbys; add replConfigPush handler

- config_repl.c: add handle_repl_config_push — standby handler for
  OPCode_replConfigPush. Verifies SHA-256, saves blob to disk via
  conf_save_config, reloads via load_primary_config, ACKs primary.
- config_repl.h: declare handle_repl_config_push.
- cluster.c: dispatch OPCode_replConfigPush to handle_repl_config_push;
  populate c->myhost_info.name from myconf->name (ctrl-1/ctrl-2/ctrl-3)
  instead of the static "controller" placeholder.
- ha.c: fix raft_cb_become_leader push_config_to_standbys call to pass
  real config bytes and tag read from disk (was NULL/0 — standbys got
  empty push and never saved config).
- typemap.h: add raw_sha256/raw_bytes/raw_bytes_len fields to
  repl_config_push_req_t (mirrors upgrade_config_req_t pattern).
- request.c: pre-extract List(UInt8) sha256/bytes from OPCode_replConfigPush
  before capn_free() in xce_decode(); free them in xce_free_request().
- helper.c: add all HA/replication opcode names to xce_request_op_name
  so "unknown opcode 30" becomes "replConfigPush" in logs.
- cluster_def.h: add embedded myhost_info field to cluster_t struct.
- ha.h: declare ha_start_primary_heartbeat; remove dead
  ha_find_and_connect_to_primary declaration.

src/controller/config_repl.c

@@ -675,6 +675,72 @@ int handle_config_request(cluster_t *c, endpoint_t *ep, xce_request_t *req)
     return rc2;
 }
 
+/* ── handle_repl_config_push ────────────────────────────────────────────────
+ *
+ * Standby handler for OPCode_replConfigPush sent by the primary.
+ *
+ * Steps:
+ *   1. Extract raw bytes + sha256 from the pre-decoded request
+ *   2. Verify SHA-256 integrity
+ *   3. Save to disk via conf_save_config
+ *   4. Reload cluster_config in memory via load_primary_config
+ *   5. Send ReplConfigPushReply with accepted=1
+ */
+int handle_repl_config_push(cluster_t *c, endpoint_t *ep, xce_request_t *req)
+{
+    if (req->body_which != Request_body_replconfigpushrequestmsg
+        || !req->body.replconfigpushrequestmsg) {
+        WARN("handle_repl_config_push: malformed request");
+        return -EINVAL;
+    }
+
+    repl_config_push_req_t *rcpr = req->body.replconfigpushrequestmsg;
+
+    if (!rcpr->raw_bytes || rcpr->raw_bytes_len == 0 || !rcpr->raw_sha256) {
+        WARN("handle_repl_config_push: missing bytes or sha256 (tag=%016" PRIx64 ")",
+             rcpr->version_tag);
+        return -EINVAL;
+    }
+
+    /* Verify transit SHA-256 */
+    uint8_t computed[32];
+    SHA256(rcpr->raw_bytes, rcpr->raw_bytes_len, computed);
+    if (memcmp(computed, rcpr->raw_sha256, 32) != 0) {
+        WARN("handle_repl_config_push: SHA-256 mismatch — rejecting push");
+        return -EBADMSG;
+    }
+
+    /* Save to disk and reload */
+    int rc = conf_save_config(c->myconf, rcpr->raw_bytes, rcpr->raw_bytes_len,
+                              rcpr->raw_sha256);
+    if (rc != 0) {
+        WARN("handle_repl_config_push: conf_save_config failed: %d", rc);
+        return rc;
+    }
+
+    rc = load_primary_config(c);
+    if (rc != 0) {
+        WARN("handle_repl_config_push: load_primary_config failed: %d", rc);
+        return rc;
+    }
+
+    INFO("handle_repl_config_push: config saved and loaded (tag=%016" PRIx64 ")",
+         c->myconf->config_version_tag);
+
+    /* ACK the primary */
+    repl_config_push_reply_t reply_body = {
+        .accepted    = 1,
+        .version_tag = c->myconf->config_version_tag,
+    };
+    xce_reply_t reply;
+    init_reply_by_req(&reply, req);
+    reply.status                      = 0;
+    reply.data_which                  = RequestReply_data_replconfigpushreplymsg;
+    reply.data.replconfigpushreplymsg = &reply_body;
+    xce_reply(ep, c->myhost, &reply);
+    return 0;
+}
+
 /* ── send_upgrade_error ─────────────────────────── */
 
 static void send_upgrade_error(endpoint_t *ep, xce_request_t *req,