fix(agents): drop confusing "default" badge from model picker (MUL-2477)

The model dropdown already exposes a "Default (provider)" option meaning
"follow the CLI's current selection". Tagging the runtime's preferred
model with a small "default" chip created two competing notions of
"default" in the same UI and confused users. Remove the chip from both
the create-agent ModelDropdown and the inspector ModelPicker; keep the
underlying RuntimeModel.default flag intact since thinking-prop-row
still uses it as a fallback heuristic.

Co-authored-by: multica-agent <github@multica.ai>

packages/views/agents/components/inspector/model-picker.tsx

@@ -153,14 +153,7 @@ export function ModelPicker({
                 `<span block text-left>` to keep layout deterministic —
                 matches the fix already applied in thinking-picker.tsx. */}
             <span className="block min-w-0 flex-1 text-left">
-              <span className="flex items-center gap-1.5">
-                <span className="truncate text-[13px] font-medium">{m.label}</span>
-                {m.default && (
-                  <span className="shrink-0 rounded bg-primary/10 px-1 text-[10px] font-medium text-primary">
-                    {t(($) => $.pickers.model_default_badge)}
-                  </span>
-                )}
-              </span>
+              <span className="block truncate text-[13px] font-medium">{m.label}</span>
               {m.label !== m.id && (
                 <span className="mt-0.5 block truncate font-mono text-[10px] leading-snug text-muted-foreground">
                   {m.id}

packages/views/agents/components/model-dropdown.tsx

@@ -183,14 +183,7 @@ export function ModelDropdown({
                       }`}
                     >
                       <div className="min-w-0 flex-1">
-                        <div className="flex items-center gap-1.5">
-                          <span className="truncate font-medium">{m.label}</span>
-                          {m.default && (
-                            <span className="shrink-0 rounded bg-primary/10 px-1.5 py-0.5 text-xs font-medium text-primary">
-                              {t(($) => $.pickers.model_default_badge)}
-                            </span>
-                          )}
-                        </div>
+                        <div className="truncate font-medium">{m.label}</div>
                         {m.label !== m.id && (
                           <div className="truncate text-xs text-muted-foreground">
                             {m.id}

packages/views/locales/en/agents.json

@@ -167,7 +167,6 @@
     "model_managed_by_runtime": "Managed by runtime",
     "model_search_placeholder": "Search or type a model ID",
     "model_discovering": "Discovering models…",
-    "model_default_badge": "default",
     "model_empty": "No models available",
     "model_empty_with_dot": "No models available.",
     "model_custom_tooltip": "Use \"{{value}}\" as a custom model id",

packages/views/locales/zh-Hans/agents.json

@@ -163,7 +163,6 @@
     "model_managed_by_runtime": "由运行时管理",
     "model_search_placeholder": "搜索或输入模型 ID",
     "model_discovering": "正在发现模型...",
-    "model_default_badge": "默认",
     "model_empty": "暂无可用模型",
     "model_empty_with_dot": "暂无可用模型。",
     "model_custom_tooltip": "使用\"{{value}}\"作为自定义模型 ID",