fix(ui): prevent UI from dropping partial chunks during stream tail parsing

Added a catch-all parsing step at the very end of the streaming loop, and within the flushed chunk loop, so any straggler text that wasn't accompanied by a finish_reason chunk or was buffered in streamDecoder.flush() is properly parsed into visible content before the DB insert.

tauri-app/src/components/ChatView.tsx

@@ -478,6 +478,7 @@ interface Props {
             try {
               const chunk = JSON.parse(data);
               const delta = chunk.choices?.[0]?.delta?.content;
+              const finishReason = chunk.choices?.[0]?.finish_reason;
               if (typeof delta === "string") {
                 const sanitizedDelta = sanitizeMessageText(delta);
                 tokenCount++;
@@ -485,12 +486,24 @@ interface Props {
                 fullContent += sanitizedDelta.text;
                 streamContentAccRef.current = fullContent;
               }
+              if (finishReason) {
+                const parsed = parseAssistantResponse(fullContent);
+                setStreamContent(parsed.content);
+                setStreamReasoning(parsed.reasoning);
+                setStreamThinkingOpen(parsed.thinkingOpen);
+              }
               if (chunk.usage) usage = chunk.usage;
             } catch (chunkErr) {
               devLog.logStreamChunk(line, null, null, `Parse error: ${chunkErr}`);
             }
           }
         }
+        
+        // Final safety parsing step to ensure UI states match DB right before saving
+        const parsed = parseAssistantResponse(fullContent);
+        setStreamContent(parsed.content);
+        setStreamReasoning(parsed.reasoning);
+        setStreamThinkingOpen(parsed.thinkingOpen);
       } else {
         const data = await res.json();
         const rawNonStream = data.choices?.[0]?.message?.content || "";