Add Typed Display Settings Administration

Implements admin-only Display settings with generation-checked
Apply, Save, Load, Defaults, and Reset operations across the web UI,
CLI, SSH dispatcher, and local UI owner. Adds bounded HTTP handling,
session-isolated operation results, browser lifecycle support, and
comprehensive host tests and documentation.

tests/admin_console_boundary/test.c

@@ -364,5 +364,20 @@ int main(void)
     assert(serial_settings_executed == 31 && network_settings_executed == 32 && account_settings_executed == 33);
     assert(runs == before_serial + 5 && s_request_queue->capacity == 4);
     puts("PASS: typed Network queues only an ID, shares unchanged queue, executes outside lock without command runner");
+    assert(admin_ssh_console_submit_display_settings(0) == ESP_ERR_INVALID_STATE);
+    s_dispatch_ready = false;
+    assert(admin_ssh_console_submit_display_settings(1) == ESP_ERR_INVALID_STATE);
+    s_dispatch_ready = true; queue_full = true;
+    assert(admin_ssh_console_submit_display_settings(1) == ESP_ERR_TIMEOUT && queue_send_wait == 0);
+    queue_full = false;
+    assert(admin_ssh_console_submit_serial_settings(41) == ESP_OK);
+    assert(admin_ssh_console_submit_network_settings(42) == ESP_OK);
+    assert(admin_ssh_console_submit_account_settings(43) == ESP_OK);
+    assert(admin_ssh_console_submit_display_settings(44) == ESP_OK && queue_send_wait == 0);
+    assert(admin_ssh_console_submit_display_settings(45) == ESP_ERR_TIMEOUT && s_request_queue->count == 4);
+    pump(worker_task);
+    assert(serial_settings_executed == 41 && network_settings_executed == 42 && account_settings_executed == 43 && display_settings_executed == 44);
+    assert(runs == before_serial + 5 && s_request_queue->capacity == 4);
+    puts("PASS: typed Display IDs share all four unchanged queue slots; full/not-ready admission fails, routing never invokes command runner");
     puts("PASS: admission/identity, two owners, completion contention/reopen, history, queued stale/revoked work, UART dispatch, hidden/disconnected prompts, exit-to-SELF_CLOSE, deferred rejection/drain/close, 5s output backpressure");
 }