fix(acms): convert ContextPolicyConfig and ViewPolicyConfiguration to Pydantic BaseModel

The two dataclasses used @dataclass decorator without importing it from
dataclasses, causing a NameError on import. This also violated the
architecture invariant that requires all dataclasses to use Pydantic
BaseModel instead of @dataclass.

Replace @dataclass with BaseModel inheritance and field(default_factory=...)
with Field(default_factory=...) which was already imported from pydantic.

src/cleveragents/acms/context_policy_loader.py

@@ -8,15 +8,14 @@ with scope rules, priority weights, and budget overrides.
 from __future__ import annotations
 
 import tomllib
-from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Any, ClassVar
 
 import yaml
+from pydantic import BaseModel, Field
 
 
-@dataclass
-class PolicyScope:
+class PolicyScope(BaseModel):
     """Represents a scope rule for context policy application."""
 
     name: str
@@ -45,8 +44,7 @@ class PolicyScope:
         return context_value in scope_values
 
 
-@dataclass
-class ContextPolicyConfig:
+class ContextPolicyConfig(BaseModel):
     """Configuration for a context policy."""
 
     name: str
@@ -55,7 +53,7 @@ class ContextPolicyConfig:
     description: str | None = None
     """Description of the policy."""
 
-    scopes: list[PolicyScope] = field(default_factory=list)
+    scopes: list[PolicyScope] = Field(default_factory=list)
     """List of scope rules for this policy."""
 
     priority_weight: float = 1.0
@@ -67,18 +65,17 @@ class ContextPolicyConfig:
     enabled: bool = True
     """Whether this policy is enabled."""
 
-    metadata: dict[str, Any] = field(default_factory=dict)
+    metadata: dict[str, Any] = Field(default_factory=dict)
     """Additional metadata for the policy."""
 
 
-@dataclass
-class ViewPolicyConfiguration:
+class ViewPolicyConfiguration(BaseModel):
     """Configuration for policies applied to a specific view."""
 
     view_name: str
     """Name of the view."""
 
-    policies: list[ContextPolicyConfig] = field(default_factory=list)
+    policies: list[ContextPolicyConfig] = Field(default_factory=list)
     """List of policies for this view."""
 
     default_priority_weight: float = 1.0
@@ -87,7 +84,7 @@ class ViewPolicyConfiguration:
     default_budget: int | None = None
     """Default budget for this view."""
 
-    metadata: dict[str, Any] = field(default_factory=dict)
+    metadata: dict[str, Any] = Field(default_factory=dict)
     """Additional metadata for the view."""