✨ feat: Add model icon support across backend and UI; prefer model icon over vendor; add icon column in Models table

Backend:
- Model: Add `icon` field to `model.Model` (gorm: varchar(128)); auto-migrated via GORM.
- Pricing API: Extend `model.Pricing` with `icon` and populate from model meta in `GetPricing()`.

Frontend:
- EditModelModal: Add `icon` input (with @lobehub/icons helper link); wire into init/load/submit flows.
- ModelHeader / PricingCardView: Prefer rendering `model.icon`; fallback to `vendor_icon`; final fallback to initials avatar.
- Models table: Add leading “Icon” column, rendering `model.icon` or `vendor` icon via `getLobeHubIcon`.

Notes:
- Backward-compatible. Existing data without `icon` remain unaffected.
- No manual SQL needed; column is added by AutoMigrate.

Affected files:
- model/model_meta.go
- model/pricing.go
- web/src/components/table/models/modals/EditModelModal.jsx
- web/src/components/table/model-pricing/modal/components/ModelHeader.jsx
- web/src/components/table/model-pricing/view/card/PricingCardView.jsx
- web/src/components/table/models/ModelsColumnDefs.js

web/src/components/table/model-pricing/modal/components/ModelHeader.jsx

@@ -29,9 +29,19 @@ const CARD_STYLES = {
 };
 
 const ModelHeader = ({ modelData, vendorsMap = {}, t }) => {
-  // 获取模型图标（使用供应商图标）
+  // 获取模型图标（优先模型图标，其次供应商图标）
   const getModelIcon = () => {
-    // 优先使用供应商图标
+    // 1) 优先使用模型自定义图标
+    if (modelData?.icon) {
+      return (
+        <div className={CARD_STYLES.container}>
+          <div className={CARD_STYLES.icon}>
+            {getLobeHubIcon(modelData.icon, 32)}
+          </div>
+        </div>
+      );
+    }
+    // 2) 退化为供应商图标
     if (modelData?.vendor_icon) {
       return (
         <div className={CARD_STYLES.container}>

web/src/components/table/model-pricing/view/card/PricingCardView.jsx

@@ -81,7 +81,17 @@ const PricingCardView = ({
         </div>
       );
     }
-    // 优先使用供应商图标
+    // 1) 优先使用模型自定义图标
+    if (model.icon) {
+      return (
+        <div className={CARD_STYLES.container}>
+          <div className={CARD_STYLES.icon}>
+            {getLobeHubIcon(model.icon, 32)}
+          </div>
+        </div>
+      );
+    }
+    // 2) 退化为供应商图标
     if (model.vendor_icon) {
       return (
         <div className={CARD_STYLES.container}>