refactor(agents): move filesystem_state, path_resolver, sandbox to app/agents/shared (slice 3b)

Relocate three leaf filesystem-cluster modules to the shared kernel and flip
all 38 importers. No re-export shims needed (no frozen single-agent importer).
This also resolves the pre-existing shared->new_chat back-edge from
shared/receipt_command.py onto filesystem_state.

filesystem_backends is intentionally deferred to slice 5: it depends on
new_chat middleware (kb_postgres_backend, multi_root_local_folder_backend)
that have not yet moved, so relocating it now would create a shared->new_chat edge.

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/middleware/middleware.py

@@ -8,8 +8,8 @@ from deepagents import FilesystemMiddleware
 from langchain_core.tools import BaseTool
 
 from app.agents.shared.filesystem_selection import FilesystemMode
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
-from app.agents.new_chat.sandbox import is_sandbox_enabled
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.sandbox import is_sandbox_enabled
 
 from ..system_prompt import build_system_prompt
 from ..tools import (

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/middleware/mode.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from app.agents.shared.filesystem_selection import FilesystemMode
-from app.agents.new_chat.path_resolver import DOCUMENTS_ROOT
+from app.agents.shared.path_resolver import DOCUMENTS_ROOT
 
 
 def is_cloud(mode: FilesystemMode) -> bool:

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/middleware/namespace_policy.py

@@ -11,8 +11,8 @@ from typing import TYPE_CHECKING
 
 from langchain.tools import ToolRuntime
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
-from app.agents.new_chat.path_resolver import DOCUMENTS_ROOT
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.path_resolver import DOCUMENTS_ROOT
 
 from ..shared.paths import TEMP_PREFIX, basename
 from .mode import is_cloud

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/middleware/path_resolution.py

@@ -8,7 +8,7 @@ from typing import TYPE_CHECKING
 from langchain.tools import ToolRuntime
 
 from app.agents.shared.filesystem_selection import FilesystemMode
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.multi_root_local_folder_backend import (
     MultiRootLocalFolderBackend,
 )

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/cd/index.py

@@ -10,8 +10,8 @@ from langchain_core.messages import ToolMessage
 from langchain_core.tools import BaseTool, StructuredTool
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
-from app.agents.new_chat.path_resolver import DOCUMENTS_ROOT
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.path_resolver import DOCUMENTS_ROOT
 
 from ...middleware.async_dispatch import run_async_blocking
 from ...middleware.path_resolution import resolve_relative

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/edit_file/index.py

@@ -11,7 +11,7 @@ from langchain_core.messages import ToolMessage
 from langchain_core.tools import BaseTool, StructuredTool
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.kb_postgres_backend import KBPostgresBackend
 
 from ...middleware.async_dispatch import run_async_blocking

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/execute_code/helpers.py

@@ -14,8 +14,8 @@ from typing import TYPE_CHECKING
 from daytona.common.errors import DaytonaError
 from langchain.tools import ToolRuntime
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
-from app.agents.new_chat.sandbox import (
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.sandbox import (
     _evict_sandbox_cache,
     delete_sandbox,
     get_or_create_sandbox,

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/execute_code/index.py

@@ -7,7 +7,7 @@ from typing import TYPE_CHECKING, Annotated
 from langchain.tools import ToolRuntime
 from langchain_core.tools import BaseTool, StructuredTool
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 
 from ...middleware.async_dispatch import run_async_blocking
 from .description import select_description

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/list_tree/index.py

@@ -9,7 +9,7 @@ from deepagents.backends.utils import validate_path
 from langchain.tools import ToolRuntime
 from langchain_core.tools import BaseTool, StructuredTool
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.kb_postgres_backend import KBPostgresBackend
 
 from ...middleware.async_dispatch import run_async_blocking

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/ls/index.py

@@ -8,7 +8,7 @@ from deepagents.backends.utils import validate_path
 from langchain.tools import ToolRuntime
 from langchain_core.tools import BaseTool, StructuredTool
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.kb_postgres_backend import paginate_listing
 
 from ...middleware.async_dispatch import run_async_blocking

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/mkdir/index.py

@@ -11,8 +11,8 @@ from langchain_core.messages import ToolMessage
 from langchain_core.tools import BaseTool, StructuredTool
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
-from app.agents.new_chat.path_resolver import DOCUMENTS_ROOT
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.path_resolver import DOCUMENTS_ROOT
 
 from ...middleware.async_dispatch import run_async_blocking
 from ...middleware.mode import is_cloud

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/move_file/helpers.py

@@ -8,9 +8,9 @@ from langchain.tools import ToolRuntime
 from langchain_core.messages import ToolMessage
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.kb_postgres_backend import KBPostgresBackend
-from app.agents.new_chat.path_resolver import DOCUMENTS_ROOT
+from app.agents.shared.path_resolver import DOCUMENTS_ROOT
 from app.agents.shared.state_reducers import _CLEAR
 
 if TYPE_CHECKING:

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/move_file/index.py

@@ -11,7 +11,7 @@ from langchain_core.messages import ToolMessage
 from langchain_core.tools import BaseTool, StructuredTool
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 
 from ...middleware.async_dispatch import run_async_blocking
 from ...middleware.mode import is_cloud

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/pwd/index.py

@@ -7,7 +7,7 @@ from typing import TYPE_CHECKING
 from langchain.tools import ToolRuntime
 from langchain_core.tools import BaseTool, StructuredTool
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 
 from ...middleware.path_resolution import current_cwd
 from .description import select_description

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/read_file/index.py

@@ -10,7 +10,7 @@ from langchain_core.messages import ToolMessage
 from langchain_core.tools import BaseTool, StructuredTool
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.kb_postgres_backend import KBPostgresBackend
 
 from ...middleware.async_dispatch import run_async_blocking

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/rm/helpers.py

@@ -12,9 +12,9 @@ from langchain.tools import ToolRuntime
 from langchain_core.messages import ToolMessage
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.kb_postgres_backend import KBPostgresBackend
-from app.agents.new_chat.path_resolver import DOCUMENTS_ROOT
+from app.agents.shared.path_resolver import DOCUMENTS_ROOT
 from app.agents.shared.state_reducers import _CLEAR
 
 if TYPE_CHECKING:

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/rm/index.py

@@ -9,7 +9,7 @@ from langchain.tools import ToolRuntime
 from langchain_core.tools import BaseTool, StructuredTool
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 
 from ...middleware.async_dispatch import run_async_blocking
 from ...middleware.mode import is_cloud

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/rmdir/helpers.py

@@ -13,9 +13,9 @@ from langchain.tools import ToolRuntime
 from langchain_core.messages import ToolMessage
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.kb_postgres_backend import KBPostgresBackend
-from app.agents.new_chat.path_resolver import DOCUMENTS_ROOT
+from app.agents.shared.path_resolver import DOCUMENTS_ROOT
 from app.agents.shared.state_reducers import _CLEAR
 
 from ...middleware.path_resolution import current_cwd

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/rmdir/index.py

@@ -9,7 +9,7 @@ from langchain.tools import ToolRuntime
 from langchain_core.tools import BaseTool, StructuredTool
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 
 from ...middleware.async_dispatch import run_async_blocking
 from ...middleware.mode import is_cloud

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/tools/write_file/index.py

@@ -11,7 +11,7 @@ from langchain_core.messages import ToolMessage
 from langchain_core.tools import BaseTool, StructuredTool
 from langgraph.types import Command
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 
 from ...middleware.async_dispatch import run_async_blocking
 from ...middleware.mode import is_cloud

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/kb_context_projection.py

@@ -9,7 +9,7 @@ from langchain.agents.middleware import AgentMiddleware, AgentState
 from langchain_core.messages import SystemMessage
 from langgraph.runtime import Runtime
 
-from app.agents.new_chat.filesystem_state import SurfSenseFilesystemState
+from app.agents.shared.filesystem_state import SurfSenseFilesystemState
 from app.agents.new_chat.middleware.knowledge_search import _render_priority_message
 from app.utils.perf import get_perf_logger