feat: merge display-fix — touch driver, keyboard, WiFi setup UI

Squash-merge of feature/display-fix (27 commits):
- AXS15231B touch driver with coordinate parsing (touch.c/h)
- On-screen keyboard with layout/hit detection (keyboard.c/h)
- WiFi setup state machine + config_add_wifi (wifi_setup.c/h)
- Web-based WiFi setup via captive portal
- Display rotation fix (stride=480), color fixes, DMA byte-swap
- WiFi QR code on BOOT and ERROR screens
- ERROR state transition after WiFi retries exhausted
- Unit tests: test_touch, test_keyboard, test_wifi_setup
- Integration test: wifi_setup.mjs
- E2E test: wifi-setup.spec.mjs
- Per-board hardware locks for flash targets

Conflicts resolved: took master for config/cvm/api/main (more current),
took display-fix for display/axs15231b (newer fixes).

1 files changed, 1 insertions, 0 deletions

diff --git a/main/config.h b/main/config.h
index 50f7efb..3092306 100644
--- a/main/config.h
+++ b/main/config.h
@@ -105,5 +105,6 @@ esp_err_t tollgate_config_init(void);
 const tollgate_config_t *tollgate_config_get(void);
 esp_err_t tollgate_config_get_wifi(wifi_config_t *wifi_config);
 esp_err_t tollgate_config_get_next_wifi(wifi_config_t *wifi_config);
+esp_err_t tollgate_config_add_wifi(const char *ssid, const char *password);
 
 #endif