feat: add Soil Moisture Sensor card to web flasher UI

Add the soil moisture sensor firmware card to the Seeed-Specific Firmware
section in the web flasher HTML page.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: limengdu

docs/flasher/index.html

@@ -389,6 +389,31 @@ <h2 class="section-title" data-en="Seeed-Specific Firmware" data-zh="Seeed 专
                     <div class="unsupported" data-en="Browser not supported" data-zh="浏览器不支持">Browser not supported</div>
                 </div>
 
+                <!-- Soil Moisture Sensor -->
+                <div class="firmware-card">
+                    <div class="card-header">
+                        <div class="card-icon">🌱</div>
+                        <div>
+                            <div class="card-title" data-en="Soil Moisture Sensor" data-zh="土壤湿度传感器">Soil Moisture Sensor</div>
+                            <div class="card-chips">
+                                <span class="card-chip seeed">XIAO ESP32-C6</span>
+                            </div>
+                        </div>
+                    </div>
+                    <p class="card-description" data-en="Soil moisture sensor with LED indicators. Supports dry/normal/wet level detection with visual feedback." data-zh="带 LED 指示灯的土壤湿度传感器。支持干燥/正常/湿润等级检测，并提供可视化反馈。">
+                        Soil moisture sensor with LED indicators. Supports dry/normal/wet level detection with visual feedback.
+                    </p>
+                    <div class="card-features">
+                        <span class="feature-tag" data-en="Soil Moisture" data-zh="土壤湿度">Soil Moisture</span>
+                        <span class="feature-tag" data-en="LED Indicator" data-zh="LED 指示灯">LED Indicator</span>
+                        <span class="feature-tag" data-en="ADC" data-zh="ADC">ADC</span>
+                    </div>
+                    <esp-web-install-button manifest="./firmware/XIAO_Soil_Moisture_Sensor/manifest.json">
+                        <button slot="activate" data-en="Install Firmware" data-zh="安装固件">Install Firmware</button>
+                    </esp-web-install-button>
+                    <div class="unsupported" data-en="Browser not supported" data-zh="浏览器不支持">Browser not supported</div>
+                </div>
+                
                 <!-- Camera Stream -->
                 <div class="firmware-card">
                     <div class="card-header">