Refactor and enhance OCR and API functionalities

- Removed obsolete unit tests for TTS/ASR module.
- Deleted unused sample video file.
- Introduced OCRImageWrapper component for better OCR image handling with loading, success, and failure states.
- Updated copilot plugin to improve transaction handling and added new types for better type safety.
- Enhanced web search block plugin to support streaming content updates.
- Refactored API utility functions for better error handling and consistency across requests.
- Added new configuration for OCR API endpoint.
- Consolidated SSE event parsing into a shared utility.
- Created string utility functions to reduce code duplication.
- Removed outdated test documents related to compression functionality.

backend/job_handlers.py

@@ -639,7 +639,12 @@ async def web_search_handler(
             f"原始上下文：\n{context}\n\n"
             f"抓取内容：\n{crawled_text}"
         )
-        synthesis_result = await call_ollama(
+
+        # 流式合成 — 逐 delta emit，前端可实时渲染
+        from llm import stream_ollama_events
+
+        accumulated: list[str] = []
+        async for event_type, text in stream_ollama_events(
             synthesis_prompt,
             system_prompt="Return only the final markdown body with no title and no citations list.",
             tag=f'{payload["request_id"][:8]}-webf',
@@ -647,8 +652,15 @@ async def web_search_handler(
             thinking=policy.get("thinking"),
             model=policy.get("model"),
             max_output_tokens=int(policy.get("max_output_tokens", 0) or 0),
-        )
-        content = _normalize_multiline_text(synthesis_result.get("content") or "")
+        ):
+            if is_cancelled():
+                raise asyncio.CancelledError()
+            # 只推送 content delta，不展示 thinking
+            if event_type == "content":
+                accumulated.append(text)
+                await emit("delta", {"text": text})
+
+        content = _normalize_multiline_text("".join(accumulated))
         if not content:
             raise RuntimeError("联网搜索生成了空结果")
         created_at = str(req.get("created_at") or payload.get("created_at") or "").strip() or datetime.now().isoformat()