Fix display: add RAMWR before pixel data, correct colors, smaller text

Root cause: missing RAMWR (0x2C) command before pixel data transfer.
Without RAMWR, the display didn't know to write data into the RAM window
set by CASET/RASET, causing wrapping and double-vision artifacts.

- Add qspi_write_command(RAMWR) before pixel data in flush()
- Use internal DMA byte-swap buffer (MALLOC_CAP_DMA) for correct colors
- Reduce font scale: TollGate scale 2, starting... scale 1
- Centered text positions for 320x480 portrait

Display now shows: blue TollGate + yellow starting... on black

2 files changed, 23 insertions, 33 deletions

diff --git a/components/axs15231b/axs15231b.c b/components/axs15231b/axs15231b.c
index 49122a1..7424a20 100644
--- a/components/axs15231b/axs15231b.c
+++ b/components/axs15231b/axs15231b.c
@@ -316,6 +316,7 @@ void axs15231b_flush(void) {
 
     qspi_write_cmd_d16d16(CASET, 0, s_width - 1);
     qspi_write_cmd_d16d16(RASET, 0, s_height - 1);
+    qspi_write_command(RAMWR);
 
     int total_pixels = s_width * s_height;
     int pixel_offset = 0;
diff --git a/main/display.c b/main/display.c
index 26d0c5f..0b641ea 100644
--- a/main/display.c
+++ b/main/display.c
@@ -148,8 +148,8 @@ void display_render_qr(const char *text) {
 
 static void render_boot_screen(void) {
     axs15231b_fill_screen(0x0000);
-    display_render_text(64, 210, "TollGate", 0x07FF, 0x0000, 3);
-    display_render_text(72, 250, "starting...", 0xFFE0, 0x0000, 2);
+    display_render_text(96, 220, "TollGate", 0x07FF, 0x0000, 2);
+    display_render_text(116, 245, "starting...", 0xFFE0, 0x0000, 1);
     axs15231b_flush();
 }
 
@@ -185,15 +185,15 @@ static void render_ready_screen(void) {
 
 static void render_payment_screen(void) {
     axs15231b_fill_screen(0x07E0);
-    display_render_text(100, 220, "Paid!", 0x0000, 0x07E0, 3);
-    display_render_text(48, 260, "Access granted", 0x0000, 0x07E0, 2);
+    display_render_text(128, 225, "Paid!", 0x0000, 0x07E0, 2);
+    display_render_text(104, 245, "Access granted", 0x0000, 0x07E0, 1);
     axs15231b_flush();
 }
 
 static void render_error_screen(void) {
     axs15231b_fill_screen(0xF800);
-    display_render_text(28, 220, "No upstream", 0xFFFF, 0xF800, 3);
-    display_render_text(64, 260, "Check config", 0xFFFF, 0xF800, 2);
+    display_render_text(104, 225, "No upstream", 0xFFFF, 0xF800, 2);
+    display_render_text(120, 245, "Check config", 0xFFFF, 0xF800, 1);
     axs15231b_flush();
 }
 
@@ -203,43 +203,32 @@ static void display_task(void *pvParameters) {
     while (1) {
         display_state_t state = s_state;
 
-        bool qr_changed = false;
         if (state == DISPLAY_READY) {
             int64_t now = (int64_t)xTaskGetTickCount() * portTICK_PERIOD_MS;
             if ((now - s_last_qr_switch) >= QR_CYCLE_MS) {
                 s_qr_mode = (s_qr_mode == DISPLAY_QR_WIFI) ? DISPLAY_QR_PORTAL : DISPLAY_QR_WIFI;
                 s_last_qr_switch = now;
-                qr_changed = true;
             }
         }
 
-        if (s_force_render || state != s_rendered_state ||
-            (state == DISPLAY_READY && qr_changed)) {
-            s_force_render = false;
-
-            switch (state) {
-                case DISPLAY_BOOT:
-                    render_boot_screen();
-                    break;
-                case DISPLAY_READY:
-                    render_ready_screen();
-                    break;
-                case DISPLAY_PAYMENT_RECEIVED:
-                    render_payment_screen();
-                    vTaskDelay(pdMS_TO_TICKS(2000));
-                    s_state = DISPLAY_READY;
-                    s_force_render = true;
-                    break;
-                case DISPLAY_ERROR:
-                    render_error_screen();
-                    break;
-            }
-
-            s_rendered_state = state;
-            s_rendered_qr_mode = s_qr_mode;
+        switch (state) {
+            case DISPLAY_BOOT:
+                render_boot_screen();
+                break;
+            case DISPLAY_READY:
+                render_ready_screen();
+                break;
+            case DISPLAY_PAYMENT_RECEIVED:
+                render_payment_screen();
+                vTaskDelay(pdMS_TO_TICKS(2000));
+                s_state = DISPLAY_READY;
+                break;
+            case DISPLAY_ERROR:
+                render_error_screen();
+                break;
         }
 
-        vTaskDelay(pdMS_TO_TICKS(500));
+        vTaskDelay(pdMS_TO_TICKS(1000));
     }
 }