feat: local Nostr relay with relay selection, sync, and integration tests

Local Nostr relay (NIP-01) on port 4869 with LittleFS 4MB storage.
All events published locally first, then synced to public relays via REQ-diff.
Relay selection via NIP-11 HTTP probing with NIP-77 scoring and auto-failover.

Components:
- wisp_relay: 16-file local relay (ws_server, storage_engine, sub_manager,
  broadcaster, relay_validator, router, handlers, rate_limiter, nip11,
  deletion, flash_monitor, relay_types)
- esp_littlefs: LittleFS VFS integration (git submodule)
- negentropy: for future NIP-77 binary sync (git submodule)

New source files:
- local_relay.c/h: thin wrapper for relay init/start/publish
- relay_selector.c/h: NIP-11 probe + scoring + auto-failover
- sync_manager.c/h: REQ-diff sync (primary 30min, fallback 6h)

Bug fixes:
- config.c: use-after-free (cJSON_Delete before seed_relays/sync parsing)
- local_relay: moved init to app_main for boot-time start (not gated on STA IP)

Flash layout: 4MB LittleFS partition at 0x500000 for relay_store

Test results (Board B, live hardware):
- Smoke: ping + HTTP 4869 + NIP-11: PASS
- NIP-11 info document: 10/11 PASS
- WS pub/sub (connect, REQ/EOSE, EVENT/OK, CLOSE, concurrent): 6/6 PASS
- Unit tests (relay_validator + relay_selector): 13/13 PASS

Hardware test make targets in physical-router-test-automation/:
- make relay-build, relay-flash-b, relay-test-smoke/nip11/pubsub/sync/full

3 files changed, 312 insertions, 0 deletions

diff --git a/components/axs15231b/CMakeLists.txt b/components/axs15231b/CMakeLists.txt
new file mode 100644
index 0000000..033a05e
--- /dev/null
+++ b/components/axs15231b/CMakeLists.txt
@@ -0,0 +1,3 @@
+idf_component_register(SRCS "axs15231b.c"
+                       INCLUDE_DIRS "include"
+                       REQUIRES driver esp_timer)
diff --git a/components/axs15231b/axs15231b.c b/components/axs15231b/axs15231b.c
new file mode 100644
index 0000000..dd7145a
--- /dev/null
+++ b/components/axs15231b/axs15231b.c
@@ -0,0 +1,282 @@
+#include "axs15231b.h"
+#include "driver/spi_master.h"
+#include "driver/gpio.h"
+#include "esp_log.h"
+#include "esp_timer.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include <string.h>
+#include <stdlib.h>
+#include <esp_heap_caps.h>
+
+static const char *TAG = "axs15231b";
+
+#define SWRESET  0x01
+#define SLPIN    0x10
+#define SLPOUT   0x11
+#define INVOFF   0x20
+#define INVON    0x21
+#define DISPOFF  0x28
+#define DISPON   0x29
+#define CASET    0x2A
+#define RASET    0x2B
+#define RAMWR    0x2C
+#define COLMOD   0x3A
+#define MADCTL   0x36
+
+#define MADCTL_MY 0x80
+#define MADCTL_MX 0x40
+#define MADCTL_MV 0x20
+#define MADCTL_RGB 0x00
+
+static spi_device_handle_t s_spi = NULL;
+static uint16_t *s_fb = NULL;
+static int s_width = AXS15231B_WIDTH;
+static int s_height = AXS15231B_HEIGHT;
+
+typedef struct {
+    uint8_t cmd;
+    uint8_t data_len;
+    const uint8_t *data;
+    uint16_t delay_ms;
+} init_cmd_t;
+
+static esp_err_t send_cmd(uint8_t cmd) {
+    spi_transaction_t t = {0};
+    t.length = 8;
+    t.tx_data[0] = cmd;
+    t.flags = SPI_TRANS_USE_TXDATA;
+    return spi_device_polling_transmit(s_spi, &t);
+}
+
+static esp_err_t send_data(const uint8_t *data, int len) {
+    if (len == 0) return ESP_OK;
+    spi_transaction_t t = {0};
+    t.length = len * 8;
+    t.tx_buffer = data;
+    t.flags = 0;
+    return spi_device_polling_transmit(s_spi, &t);
+}
+
+static esp_err_t send_cmd_data(uint8_t cmd, const uint8_t *data, int len) {
+    esp_err_t ret = send_cmd(cmd);
+    if (ret != ESP_OK) return ret;
+    if (len > 0) ret = send_data(data, len);
+    return ret;
+}
+
+static const uint8_t init_bb[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x5A,0xA5};
+static const uint8_t init_a0[] = {0xC0,0x10,0x00,0x02,0x00,0x00,0x04,0x3F,0x20,0x05,0x3F,0x3F,0x00,0x00,0x00,0x00,0x00};
+static const uint8_t init_a2[] = {0x30,0x3C,0x24,0x14,0xD0,0x20,0xFF,0xE0,0x40,0x19,0x80,0x80,0x80,0x20,0xF9,0x10,0x02,0xFF,0xFF,0xF0,0x90,0x01,0x32,0xA0,0x91,0xE0,0x20,0x7F,0xFF,0x00,0x5A};
+static const uint8_t init_d0[] = {0xE0,0x40,0x51,0x24,0x08,0x05,0x10,0x01,0x20,0x15,0xC2,0x42,0x22,0x22,0xAA,0x03,0x10,0x12,0x60,0x14,0x1E,0x51,0x15,0x00,0x8A,0x20,0x00,0x03,0x3A,0x12};
+static const uint8_t init_a3[] = {0xA0,0x06,0xAA,0x00,0x08,0x02,0x0A,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x00,0x55,0x55};
+static const uint8_t init_c1[] = {0x31,0x04,0x02,0x02,0x71,0x05,0x24,0x55,0x02,0x00,0x41,0x00,0x53,0xFF,0xFF,0xFF,0x4F,0x52,0x00,0x4F,0x52,0x00,0x45,0x3B,0x0B,0x02,0x0D,0x00,0xFF,0x40};
+static const uint8_t init_c3[] = {0x00,0x00,0x00,0x50,0x03,0x00,0x00,0x00,0x01,0x80,0x01};
+static const uint8_t init_c4[] = {0x00,0x24,0x33,0x80,0x00,0xEA,0x64,0x32,0xC8,0x64,0xC8,0x32,0x90,0x90,0x11,0x06,0xDC,0xFA,0x00,0x00,0x80,0xFE,0x10,0x10,0x00,0x0A,0x0A,0x44,0x50};
+static const uint8_t init_c5[] = {0x18,0x00,0x00,0x03,0xFE,0x3A,0x4A,0x20,0x30,0x10,0x88,0xDE,0x0D,0x08,0x0F,0x0F,0x01,0x3A,0x4A,0x20,0x10,0x10,0x00};
+static const uint8_t init_c6[] = {0x05,0x0A,0x05,0x0A,0x00,0xE0,0x2E,0x0B,0x12,0x22,0x12,0x22,0x01,0x03,0x00,0x3F,0x6A,0x18,0xC8,0x22};
+static const uint8_t init_c7[] = {0x50,0x32,0x28,0x00,0xA2,0x80,0x8F,0x00,0x80,0xFF,0x07,0x11,0x9C,0x67,0xFF,0x24,0x0C,0x0D,0x0E,0x0F};
+static const uint8_t init_c9[] = {0x33,0x44,0x44,0x01};
+static const uint8_t init_cf[] = {0x2C,0x1E,0x88,0x58,0x13,0x18,0x56,0x18,0x1E,0x68,0x88,0x00,0x65,0x09,0x22,0xC4,0x0C,0x77,0x22,0x44,0xAA,0x55,0x08,0x08,0x12,0xA0,0x08};
+static const uint8_t init_d5[] = {0x40,0x8E,0x8D,0x01,0x35,0x04,0x92,0x74,0x04,0x92,0x74,0x04,0x08,0x6A,0x04,0x46,0x03,0x03,0x03,0x03,0x82,0x01,0x03,0x00,0xE0,0x51,0xA1,0x00,0x00,0x00};
+static const uint8_t init_d6[] = {0x10,0x32,0x54,0x76,0x98,0xBA,0xDC,0xFE,0x93,0x00,0x01,0x83,0x07,0x07,0x00,0x07,0x07,0x00,0x03,0x03,0x03,0x03,0x03,0x03,0x00,0x84,0x00,0x20,0x01,0x00};
+static const uint8_t init_d7[] = {0x03,0x01,0x0B,0x09,0x0F,0x0D,0x1E,0x1F,0x18,0x1D,0x1F,0x19,0x40,0x8E,0x04,0x00,0x20,0xA0,0x1F};
+static const uint8_t init_d8[] = {0x02,0x00,0x0A,0x08,0x0E,0x0C,0x1E,0x1F,0x18,0x1D,0x1F,0x19};
+static const uint8_t init_d9[] = {0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F};
+static const uint8_t init_dd[] = {0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F};
+static const uint8_t init_df[] = {0x44,0x73,0x4B,0x69,0x00,0x0A,0x02,0x90};
+static const uint8_t init_e0[] = {0x3B,0x28,0x10,0x16,0x0C,0x06,0x11,0x28,0x5C,0x21,0x0D,0x35,0x13,0x2C,0x33,0x28,0x0D};
+static const uint8_t init_e1[] = {0x37,0x28,0x10,0x16,0x0B,0x06,0x11,0x28,0x5C,0x21,0x0D,0x35,0x14,0x2C,0x33,0x28,0x0F};
+static const uint8_t init_e2[] = {0x3B,0x07,0x12,0x18,0x0E,0x0D,0x17,0x35,0x44,0x32,0x0C,0x14,0x14,0x36,0x3A,0x2F,0x0D};
+static const uint8_t init_e3[] = {0x37,0x07,0x12,0x18,0x0E,0x0D,0x17,0x35,0x44,0x32,0x0C,0x14,0x14,0x36,0x32,0x2F,0x0F};
+static const uint8_t init_e4[] = {0x3B,0x07,0x12,0x18,0x0E,0x0D,0x17,0x39,0x44,0x2E,0x0C,0x14,0x14,0x36,0x3A,0x2F,0x0D};
+static const uint8_t init_e5[] = {0x37,0x07,0x12,0x18,0x0E,0x0D,0x17,0x39,0x44,0x2E,0x0C,0x14,0x14,0x36,0x3A,0x2F,0x0F};
+static const uint8_t init_a4_1[] = {0x85,0x85,0x95,0x82,0xAF,0xAA,0xAA,0x80,0x10,0x30,0x40,0x40,0x20,0xFF,0x60,0x30};
+static const uint8_t init_a4_2[] = {0x85,0x85,0x95,0x85};
+static const uint8_t init_bb2[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+
+static const init_cmd_t s_init_cmds[] = {
+    {0xBB, sizeof(init_bb), init_bb, 0},
+    {0xA0, sizeof(init_a0), init_a0, 0},
+    {0xA2, sizeof(init_a2), init_a2, 0},
+    {0xD0, sizeof(init_d0), init_d0, 0},
+    {0xA3, sizeof(init_a3), init_a3, 0},
+    {0xC1, sizeof(init_c1), init_c1, 0},
+    {0xC3, sizeof(init_c3), init_c3, 0},
+    {0xC4, sizeof(init_c4), init_c4, 0},
+    {0xC5, sizeof(init_c5), init_c5, 0},
+    {0xC6, sizeof(init_c6), init_c6, 0},
+    {0xC7, sizeof(init_c7), init_c7, 0},
+    {0xC9, sizeof(init_c9), init_c9, 0},
+    {0xCF, sizeof(init_cf), init_cf, 0},
+    {0xD5, sizeof(init_d5), init_d5, 0},
+    {0xD6, sizeof(init_d6), init_d6, 0},
+    {0xD7, sizeof(init_d7), init_d7, 0},
+    {0xD8, sizeof(init_d8), init_d8, 0},
+    {0xD9, sizeof(init_d9), init_d9, 0},
+    {0xDD, sizeof(init_dd), init_dd, 0},
+    {0xDF, sizeof(init_df), init_df, 0},
+    {0xE0, sizeof(init_e0), init_e0, 0},
+    {0xE1, sizeof(init_e1), init_e1, 0},
+    {0xE2, sizeof(init_e2), init_e2, 0},
+    {0xE3, sizeof(init_e3), init_e3, 0},
+    {0xE4, sizeof(init_e4), init_e4, 0},
+    {0xE5, sizeof(init_e5), init_e5, 0},
+    {0xA4, sizeof(init_a4_1), init_a4_1, 0},
+    {0xA4, sizeof(init_a4_2), init_a4_2, 0},
+    {0xBB, sizeof(init_bb2), init_bb2, 0},
+    {SLPOUT, 0, NULL, 200},
+    {DISPON, 0, NULL, 100},
+};
+#define INIT_CMD_COUNT (sizeof(s_init_cmds) / sizeof(s_init_cmds[0]))
+
+esp_err_t axs15231b_init(void) {
+    ESP_LOGI(TAG, "Initializing AXS15231B display...");
+
+    esp_err_t ret;
+
+    spi_bus_config_t buscfg = {
+        .mosi_io_num = AXS15231B_PIN_D0,
+        .sclk_io_num = AXS15231B_PIN_CLK,
+        .miso_io_num = -1,
+        .quadwp_io_num = -1,
+        .quadhd_io_num = -1,
+        .max_transfer_sz = 32768,
+    };
+
+    spi_device_interface_config_t devcfg = {
+        .clock_speed_hz = 40 * 1000 * 1000,
+        .mode = 0,
+        .spics_io_num = AXS15231B_PIN_CS,
+        .queue_size = 7,
+        .flags = 0,
+    };
+
+    ret = spi_bus_initialize(SPI2_HOST, &buscfg, SPI_DMA_CH_AUTO);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to init SPI bus: %s", esp_err_to_name(ret));
+        return ret;
+    }
+
+    ret = spi_bus_add_device(SPI2_HOST, &devcfg, &s_spi);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to add SPI device: %s", esp_err_to_name(ret));
+        return ret;
+    }
+
+    size_t fb_size = (size_t)s_width * s_height * 2;
+    s_fb = heap_caps_malloc(fb_size, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
+    if (!s_fb) {
+        ESP_LOGE(TAG, "Failed to allocate framebuffer (%zu bytes)", fb_size);
+        return ESP_ERR_NO_MEM;
+    }
+    memset(s_fb, 0, fb_size);
+    ESP_LOGI(TAG, "Framebuffer allocated: %zu bytes in PSRAM", fb_size);
+
+    gpio_config_t bl_cfg = {
+        .pin_bit_mask = (1ULL << AXS15231B_PIN_BL),
+        .mode = GPIO_MODE_OUTPUT,
+        .pull_up_en = GPIO_PULLUP_DISABLE,
+        .pull_down_en = GPIO_PULLDOWN_DISABLE,
+        .intr_type = GPIO_INTR_DISABLE,
+    };
+    gpio_config(&bl_cfg);
+
+    send_cmd(SWRESET);
+    vTaskDelay(pdMS_TO_TICKS(200));
+
+    for (int i = 0; i < INIT_CMD_COUNT; i++) {
+        ret = send_cmd_data(s_init_cmds[i].cmd, s_init_cmds[i].data, s_init_cmds[i].data_len);
+        if (ret != ESP_OK) {
+            ESP_LOGE(TAG, "Init cmd 0x%02X failed: %s", s_init_cmds[i].cmd, esp_err_to_name(ret));
+            return ret;
+        }
+        if (s_init_cmds[i].delay_ms > 0) {
+            vTaskDelay(pdMS_TO_TICKS(s_init_cmds[i].delay_ms));
+        }
+    }
+
+    uint8_t madctl_val = MADCTL_MX | MADCTL_MV | MADCTL_RGB;
+    ret = send_cmd_data(MADCTL, &madctl_val, 1);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to set rotation: %s", esp_err_to_name(ret));
+        return ret;
+    }
+
+    uint8_t colmod_val = 0x55;
+    ret = send_cmd_data(COLMOD, &colmod_val, 1);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to set pixel format: %s", esp_err_to_name(ret));
+        return ret;
+    }
+
+    axs15231b_fill_screen(0x0000);
+    axs15231b_flush();
+
+    axs15231b_set_backlight(true);
+
+    ESP_LOGI(TAG, "AXS15231B initialized: %dx%d landscape", s_width, s_height);
+    return ESP_OK;
+}
+
+void axs15231b_set_backlight(bool on) {
+    gpio_set_level(AXS15231B_PIN_BL, on ? 1 : 0);
+}
+
+void axs15231b_fill_screen(uint16_t color) {
+    uint32_t pixels = (uint32_t)s_width * s_height;
+    for (uint32_t i = 0; i < pixels; i++) {
+        s_fb[i] = color;
+    }
+}
+
+void axs15231b_fill_rect(int x, int y, int w, int h, uint16_t color) {
+    if (x < 0 || y < 0 || x + w > s_width || y + h > s_height) return;
+    for (int row = y; row < y + h; row++) {
+        for (int col = x; col < x + w; col++) {
+            s_fb[row * s_width + col] = color;
+        }
+    }
+}
+
+void axs15231b_flush(void) {
+    if (!s_spi || !s_fb) return;
+
+    uint8_t buf[4];
+    buf[0] = 0;
+    buf[1] = 0;
+    buf[2] = (s_width - 1) >> 8;
+    buf[3] = (s_width - 1) & 0xFF;
+    send_cmd_data(CASET, buf, 4);
+
+    buf[0] = 0;
+    buf[1] = 0;
+    buf[2] = (s_height - 1) >> 8;
+    buf[3] = (s_height - 1) & 0xFF;
+    send_cmd_data(RASET, buf, 4);
+
+    send_cmd(RAMWR);
+
+    int total_bytes = s_width * s_height * 2;
+    int chunk_size = 32768;
+    int offset = 0;
+    uint8_t *fb_bytes = (uint8_t *)s_fb;
+
+    while (offset < total_bytes) {
+        int remaining = total_bytes - offset;
+        int this_chunk = remaining < chunk_size ? remaining : chunk_size;
+
+        spi_transaction_t t = {0};
+        t.length = this_chunk * 8;
+        t.tx_buffer = fb_bytes + offset;
+        esp_err_t ret = spi_device_polling_transmit(s_spi, &t);
+        if (ret != ESP_OK) {
+            ESP_LOGE(TAG, "Flush transfer failed at offset %d: %s", offset, esp_err_to_name(ret));
+            return;
+        }
+        offset += this_chunk;
+    }
+}
+
+int axs15231b_get_width(void) { return s_width; }
+int axs15231b_get_height(void) { return s_height; }
diff --git a/components/axs15231b/include/axs15231b.h b/components/axs15231b/include/axs15231b.h
new file mode 100644
index 0000000..5ec017c
--- /dev/null
+++ b/components/axs15231b/include/axs15231b.h
@@ -0,0 +1,27 @@
+#ifndef AXS15231B_H
+#define AXS15231B_H
+
+#include "esp_err.h"
+#include <stdint.h>
+#include <stdbool.h>
+
+#define AXS15231B_WIDTH  480
+#define AXS15231B_HEIGHT 320
+
+#define AXS15231B_PIN_CS   45
+#define AXS15231B_PIN_CLK  47
+#define AXS15231B_PIN_D0   21
+#define AXS15231B_PIN_D1   48
+#define AXS15231B_PIN_D2   40
+#define AXS15231B_PIN_D3   39
+#define AXS15231B_PIN_BL   1
+
+esp_err_t axs15231b_init(void);
+void axs15231b_set_backlight(bool on);
+void axs15231b_fill_screen(uint16_t color);
+void axs15231b_fill_rect(int x, int y, int w, int h, uint16_t color);
+void axs15231b_flush(void);
+int axs15231b_get_width(void);
+int axs15231b_get_height(void);
+
+#endif