Add typed serial settings operations

Route bounded admin mutations through the existing administration
dispatcher,
covering apply, lifecycle, persistence, authorization, and result
tracking.
Add the browser controls, automatic result refresh, regression coverage,
and
phase documentation.

tests/web_cookie_auth/test.c

@@ -18,6 +18,7 @@ static size_t body_offset;
 static unsigned password_calls, cookie_count, sends, upgrades;
 static unsigned fail_header, setter_calls;
 static bool send_fail, recv_fail;
+static size_t receive_fragment = 7;
 static void (*password_hook)(void);
 static char response_status[48];
 static struct httpd_req_aux aux;
@@ -46,7 +47,7 @@ esp_err_t httpd_resp_sendstr(httpd_req_t *r, const char *body) {
 }
 int httpd_req_recv(httpd_req_t *r, char *out, size_t size) {
     (void)r; if (recv_fail) return -1;
-    if (size > 7) size = 7; /* Fragment every login body. */
+    if (size > receive_fragment) size = receive_fragment;
     memcpy(out, request_body + body_offset, size); body_offset += size;
     aux.remaining_len -= size; return (int)size;
 }
@@ -122,6 +123,9 @@ static void auth_reset(void) {
 #ifdef HOST_SETTINGS
 #include "settings_test.c"
 #endif
+#ifdef HOST_SERIAL_SETTINGS
+#include "serial_settings_test.c"
+#endif
 
 int main(void) {
     assert(store_tests() == 0); auth_reset();
@@ -272,6 +276,9 @@ int main(void) {
 #endif
 #ifdef HOST_SETTINGS
     settings_tests();
+#endif
+#ifdef HOST_SERIAL_SETTINGS
+    serial_settings_tests();
 #endif
     return 0;
 }