refactor(agents): move permissions to app/agents/shared (slice 4a)

Relocate the permission evaluator (wildcard matcher + rule evaluation) to the
shared kernel and flip 43 non-frozen importers. A re-export shim remains at
new_chat/permissions.py for the frozen single-agent stack (chat_deepagent and
subagents/{config,providers/linear,providers/slack}); it will be removed when
that stack is retired.

surfsense_backend/tests/unit/agents/multi_agent_chat/middleware/checkpointed_subagent_middleware/test_parallel_self_and_middleware_gated.py

@@ -49,7 +49,7 @@ from app.agents.multi_agent_chat.middleware.shared.permissions.ask.request impor
 from app.agents.multi_agent_chat.subagents.shared.hitl.approvals.self_gated import (
     request_approval,
 )
-from app.agents.new_chat.permissions import Rule
+from app.agents.shared.permissions import Rule
 
 
 class _SubState(TypedDict, total=False):

surfsense_backend/tests/unit/agents/multi_agent_chat/middleware/shared/permissions/test_lc_hitl_wire.py

@@ -19,7 +19,7 @@ from typing_extensions import TypedDict
 from app.agents.multi_agent_chat.middleware.shared.permissions.ask.request import (
     request_permission_decision,
 )
-from app.agents.new_chat.permissions import Rule
+from app.agents.shared.permissions import Rule
 
 
 class _State(TypedDict, total=False):

surfsense_backend/tests/unit/agents/multi_agent_chat/middleware/shared/permissions/test_permission_ask_mcp_context.py

@@ -20,7 +20,7 @@ from app.agents.multi_agent_chat.middleware.shared.permissions.ask.payload impor
     build_permission_ask_payload,
 )
 from app.agents.shared.feature_flags import AgentFeatureFlags
-from app.agents.new_chat.permissions import Rule, Ruleset
+from app.agents.shared.permissions import Rule, Ruleset
 
 
 class _NoArgs(BaseModel):

surfsense_backend/tests/unit/agents/multi_agent_chat/middleware/shared/permissions/test_subagent_owned_ruleset.py

@@ -27,7 +27,7 @@ from app.agents.multi_agent_chat.middleware.shared.permissions import (
     build_permission_mw,
 )
 from app.agents.shared.feature_flags import AgentFeatureFlags
-from app.agents.new_chat.permissions import Rule, Ruleset
+from app.agents.shared.permissions import Rule, Ruleset
 
 
 def _kb_style_ruleset() -> Ruleset:

surfsense_backend/tests/unit/agents/multi_agent_chat/middleware/shared/permissions/test_trusted_tool_save_on_always.py

@@ -18,7 +18,7 @@ from app.agents.multi_agent_chat.middleware.shared.permissions import (
     build_permission_mw,
 )
 from app.agents.shared.feature_flags import AgentFeatureFlags
-from app.agents.new_chat.permissions import Rule, Ruleset
+from app.agents.shared.permissions import Rule, Ruleset
 
 
 class _NoArgs(BaseModel):

surfsense_backend/tests/unit/agents/multi_agent_chat/subagents/shared/test_subagent_builder.py

@@ -26,7 +26,7 @@ from app.agents.multi_agent_chat.subagents.shared.subagent_builder import (
     pack_subagent,
 )
 from app.agents.shared.feature_flags import AgentFeatureFlags
-from app.agents.new_chat.permissions import Rule, Ruleset, evaluate
+from app.agents.shared.permissions import Rule, Ruleset, evaluate
 
 
 class RateLimitError(Exception):

surfsense_backend/tests/unit/agents/new_chat/test_default_permissions_layering.py

@@ -27,7 +27,7 @@ from __future__ import annotations
 
 import pytest
 
-from app.agents.new_chat.permissions import (
+from app.agents.shared.permissions import (
     Rule,
     Ruleset,
     aggregate_action,

surfsense_backend/tests/unit/agents/new_chat/test_desktop_safety_rules.py

@@ -11,7 +11,7 @@ from __future__ import annotations
 import pytest
 
 from app.agents.new_chat.middleware.permission import PermissionMiddleware
-from app.agents.new_chat.permissions import (
+from app.agents.shared.permissions import (
     Rule,
     Ruleset,
     aggregate_action,

surfsense_backend/tests/unit/agents/new_chat/test_permission_middleware.py

@@ -10,7 +10,7 @@ from app.agents.new_chat.middleware.permission import (
     PermissionMiddleware,
     _normalize_permission_decision,
 )
-from app.agents.new_chat.permissions import Rule, Ruleset
+from app.agents.shared.permissions import Rule, Ruleset
 
 pytestmark = pytest.mark.unit
 

surfsense_backend/tests/unit/agents/new_chat/test_permissions.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 import pytest
 
-from app.agents.new_chat.permissions import (
+from app.agents.shared.permissions import (
     Rule,
     Ruleset,
     aggregate_action,

surfsense_backend/tests/unit/agents/new_chat/test_specialized_subagents.py

@@ -332,6 +332,6 @@ class TestDenyPatternsCoverage:
 
 def _wildcard_matches(pattern: str, value: str) -> bool:
     """Helper using the same matcher the rule evaluator does."""
-    from app.agents.new_chat.permissions import wildcard_match
+    from app.agents.shared.permissions import wildcard_match
 
     return wildcard_match(value, pattern)