fix: improve MiniMax code plan integration (#1169)

This PR improves MiniMax Code Plan integration in DeerFlow by fixing three issues in the current flow: stream errors were not clearly surfaced in the UI, the frontend could not display the actual provider model ID, and MiniMax reasoning output could leak into final assistant content as inline <think>...</think>. The change adds a MiniMax-specific adapter, exposes real model IDs end-to-end, and adds a frontend fallback for historical messages.
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

frontend/src/components/workspace/input-box.tsx

@@ -702,9 +702,16 @@ export function InputBox({
           >
             <ModelSelectorTrigger asChild>
               <PromptInputButton>
-                <ModelSelectorName className="text-xs font-normal">
-                  {selectedModel?.display_name}
-                </ModelSelectorName>
+                <div className="flex min-w-0 flex-col items-start text-left">
+                  <ModelSelectorName className="text-xs font-normal">
+                    {selectedModel?.display_name}
+                  </ModelSelectorName>
+                  {selectedModel?.model && (
+                    <span className="text-muted-foreground w-full truncate text-[10px] leading-none">
+                      {selectedModel.model}
+                    </span>
+                  )}
+                </div>
               </PromptInputButton>
             </ModelSelectorTrigger>
             <ModelSelectorContent>
@@ -716,7 +723,12 @@ export function InputBox({
                     value={m.name}
                     onSelect={() => handleModelSelect(m.name)}
                   >
-                    <ModelSelectorName>{m.display_name}</ModelSelectorName>
+                    <div className="flex min-w-0 flex-1 flex-col">
+                      <ModelSelectorName>{m.display_name}</ModelSelectorName>
+                      <span className="text-muted-foreground truncate text-[10px]">
+                        {m.model}
+                      </span>
+                    </div>
                     {m.name === context.model_name ? (
                       <CheckIcon className="ml-auto size-4" />
                     ) : (