refactor: type ContextVar design state as DesignState

Change set_design_state() and get_design_state() to use DesignState
objects instead of dicts. Update QueryDesignStateTool._run() to use
the state directly without reconstruction. Update callers in
CrewOrchestrator to pass DesignState objects instead of model_dump().

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

agents/crew_orchestrator.py

@@ -181,7 +181,7 @@ class CrewOrchestrator(BaseOrchestrator):
         state = state.update_from_messages([], user_message=message)
 
         # Expose design state to the orchestrator tool so agents can query it.
-        set_design_state(state.model_dump())
+        set_design_state(state)
 
         context = _build_agent_context(message, state, approved_plan=approved_plan)
 
@@ -316,7 +316,7 @@ class CrewOrchestrator(BaseOrchestrator):
         # from user message so gap analysis reflects current turn data.
         state = DesignState(**(design_state or {}))
         state = state.update_from_messages([], user_message=message)
-        set_design_state(state.model_dump())
+        set_design_state(state)
 
         mock = MockChatBackend(output_dir=self.output_dir)
         result = mock.chat_turn(message, history, mentions, design_state=state.model_dump(), plan_context=plan_context)

agents/tools.py

@@ -12,6 +12,8 @@ from typing import Type
 
 from pydantic import BaseModel, Field
 
+from agents.design_state import DesignState
+
 logger = logging.getLogger(__name__)
 
 try:
@@ -27,7 +29,7 @@ except ImportError:
 # ── Per-request state (ContextVar — async-safe) ─────────────────────────
 
 _last_shape_var: ContextVar[object | None] = ContextVar("last_shape", default=None)
-_design_state_var: ContextVar[dict | None] = ContextVar("design_state", default=None)
+_design_state_var: ContextVar[DesignState | None] = ContextVar("design_state", default=None)
 
 
 def set_last_shape(shape):
@@ -36,10 +38,10 @@ def set_last_shape(shape):
 def get_last_shape():
     return _last_shape_var.get()
 
-def set_design_state(state_dict: dict):
-    _design_state_var.set(state_dict)
+def set_design_state(state: DesignState):
+    _design_state_var.set(state)
 
-def get_design_state() -> dict | None:
+def get_design_state() -> DesignState | None:
     return _design_state_var.get()
 
 
@@ -115,17 +117,15 @@ class QueryDesignStateTool(BaseTool):
     args_schema: Type[BaseModel] = QueryDesignStateInput
 
     def _run(self, check: str = "all") -> str:
-        from agents.design_state import DesignState, compute_score
+        from agents.design_state import compute_score
         from config.settings import settings
 
         if check not in VALID_CHECKS:
             return json.dumps({"error": f"Invalid check: {check!r}. Valid: {sorted(VALID_CHECKS)}"})
 
-        state_dict = get_design_state()
-        if state_dict is None:
+        state = get_design_state()
+        if state is None:
             return json.dumps({"error": "No design state available."})
-
-        state = DesignState(**state_dict)
         score = compute_score(state)
         threshold = settings.planning.threshold