feat: add Chinese 12x12 bitmap font (21075 glyphs) and fix boot gate

- Add ChineseFont12x12.h: U+4E00-U+9FFF CJK coverage, 535KB flash

- Add gen_chinese_font.mjs: @napi-rs/canvas based font generator tool

- Enable CJK rendering in MessageRenderer and CannedMessageModule

- Remove boot confirmation gate (required 2s button hold, caused shutdown loop)

- Update partition table: app 2.75MB, OTA 192KB, spiffs 1MB

- Update CHANGELOG

code/firmware-2.7.15.567b8ea/src/main.cpp

@@ -589,40 +589,6 @@ void setup()
     // MOS 断电，系统在 setup() 中途就会掉电。
     tca9535PowerEn(true);
     LOG_INFO("TCA9535: POWER_EN latched HIGH (early boot)");
-
-    // 开机确认窗口：检测 P1.3 是否持续按住 2 秒，防止意外通电卡死
-    // 最多等待 3 秒，3 秒内未连续按满 2 秒则断电关机
-    {
-        bool bootConfirmed = false;
-        uint32_t pressStart = 0;
-        uint32_t deadline = millis() + 3000;
-        LOG_INFO("TCA9535: Waiting for 2s button hold to confirm boot (timeout 3s)...");
-
-        while (millis() < deadline) {
-            bool pressed = tca9535ReadPowerBoot();
-            if (pressed && pressStart == 0) {
-                pressStart = millis();
-            } else if (pressed && pressStart != 0) {
-                if (millis() - pressStart >= 2000) {
-                    bootConfirmed = true;
-                    LOG_INFO("TCA9535: Boot confirmed (button held 2s)");
-                    break;
-                }
-            } else if (!pressed && pressStart != 0) {
-                // 松手重置计时
-                pressStart = 0;
-            }
-            delay(50); // 50ms 轮询
-        }
-
-        if (!bootConfirmed) {
-            LOG_WARN("TCA9535: Boot not confirmed, shutting down");
-            tca9535PowerEn(false);
-            // 等待 MOS 断开
-            delay(500);
-            doDeepSleep(0, false, false);
-        }
-    }
 #endif
 #elif defined(ARCH_PORTDUINO)
     if (portduino_config.i2cdev != "") {