fix: Add toggle for fulltext retrieval path (#1096) (#1098)

feat: Add toggle for fulltext retrieval path (FULLTEXT_CALL), default
off

## Description

Please include a summary of the change, the problem it solves, the
implementation approach, and relevant context. List any dependencies
required for this change.

Related Issue (Required):  Fixes @issue_number

## Type of change

Please delete options that are not relevant.

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Refactor (does not change functionality, e.g. code style
improvements, linting)
- [ ] Documentation update

## How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide
instructions so we can reproduce. Please also list any relevant details
for your test configuration

- [ ] Unit Test
- [ ] Test Script Or Test Steps (please provide)
- [ ] Pipeline Automated API Test (please provide)

## Checklist

- [ ] I have performed a self-review of my own code | 我已自行检查了自己的代码
- [ ] I have commented my code in hard-to-understand areas |
我已在难以理解的地方对代码进行了注释
- [ ] I have added tests that prove my fix is effective or that my
feature works | 我已添加测试以证明我的修复有效或功能正常
- [ ] I have created related documentation issue/PR in
[MemOS-Docs](https://github.com/MemTensor/MemOS-Docs) (if applicable) |
我已在 [MemOS-Docs](https://github.com/MemTensor/MemOS-Docs) 中创建了相关的文档
issue/PR（如果适用）
- [ ] I have linked the issue to this PR (if applicable) | 我已将 issue
链接到此 PR（如果适用）
- [ ] I have mentioned the person who will review this PR | 我已提及将审查此 PR
的人

## Reviewer Checklist
- [ ] closes #xxxx (Replace xxxx with the GitHub issue number)
- [ ] Made sure Checks passed
- [ ] Tests have been provided

Author: CaralHsi

src/memos/api/config.py

@@ -1014,6 +1014,7 @@ def create_user_config(user_name: str, user_id: str) -> tuple["MOSConfig", "Gene
                                 "fast_graph": bool(os.getenv("FAST_GRAPH", "false") == "true"),
                                 "bm25": bool(os.getenv("BM25_CALL", "false") == "true"),
                                 "cot": bool(os.getenv("VEC_COT_CALL", "false") == "true"),
+                                "fulltext": bool(os.getenv("FULLTEXT_CALL", "false") == "true"),
                             },
                             "include_embedding": bool(
                                 os.getenv("INCLUDE_EMBEDDING", "false") == "true"
@@ -1096,6 +1097,7 @@ def get_default_cube_config() -> "GeneralMemCubeConfig | None":
                                 "fast_graph": bool(os.getenv("FAST_GRAPH", "false") == "true"),
                                 "bm25": bool(os.getenv("BM25_CALL", "false") == "true"),
                                 "cot": bool(os.getenv("VEC_COT_CALL", "false") == "true"),
+                                "fulltext": bool(os.getenv("FULLTEXT_CALL", "false") == "true"),
                             },
                             "mode": os.getenv("ASYNC_MODE", "sync"),
                             "include_embedding": bool(

src/memos/memories/textual/tree_text_memory/retrieve/searcher.py

@@ -67,6 +67,7 @@ def __init__(
         self.internet_retriever = internet_retriever
         self.vec_cot = search_strategy.get("cot", False) if search_strategy else False
         self.use_fast_graph = search_strategy.get("fast_graph", False) if search_strategy else False
+        self.use_fulltext = search_strategy.get("fulltext", False) if search_strategy else False
         self.manual_close_internet = manual_close_internet
         self.tokenizer = tokenizer
         self._usage_executor = ContextThreadPoolExecutor(max_workers=4, thread_name_prefix="usage")
@@ -380,20 +381,21 @@ def _retrieve_paths(
                     user_name,
                 )
             )
-            tasks.append(
-                executor.submit(
-                    self._retrieve_from_keyword,
-                    query,
-                    parsed_goal,
-                    query_embedding,
-                    top_k,
-                    memory_type,
-                    search_filter,
-                    search_priority,
-                    user_name,
-                    id_filter,
+            if self.use_fulltext:
+                tasks.append(
+                    executor.submit(
+                        self._retrieve_from_keyword,
+                        query,
+                        parsed_goal,
+                        query_embedding,
+                        top_k,
+                        memory_type,
+                        search_filter,
+                        search_priority,
+                        user_name,
+                        id_filter,
+                    )
                 )
-            )
             if search_tool_memory:
                 tasks.append(
                     executor.submit(