bbdr: rename BBR log fields, add mode transition logs, configurable max inflight

src/config_parser.c

@@ -720,7 +720,7 @@ static struct utun_config* parse_config_internal(FILE *fp, const char *filename)
     cfg->global.name[0] = '\0';
     cfg->global.keepalive_timeout = 2000;  // Default 2 seconds
     cfg->global.keepalive_interval = 200;   // Default 0.2 s
-    cfg->global.bbr_max_cwnd = 100000;  // Default 100KB
+    cfg->global.bbr_max_cwnd = 1048576; // Default 1MB (was INFLIGHT_LIM_MAX)
     cfg->global.firewall_rules = NULL;
     cfg->global.firewall_rule_count = 0;
     cfg->global.firewall_bypass_all = 0;