feat: strengthen module contracts and shared WebUI runtime

src/govoplan_core/api/v1/schemas.py

@@ -39,6 +39,22 @@ class DeltaCollectionResponse(BaseModel):
     full: bool = False
 
 
+class ReferenceOptionResponse(BaseModel):
+    value: str
+    label: str
+    description: str | None = None
+    kind: str | None = None
+    availability: Literal["available", "inactive", "unavailable"] = "available"
+    disabled: bool = False
+    source_module: str | None = None
+    provenance: dict[str, Any] = Field(default_factory=dict)
+
+
+class ReferenceOptionListResponse(BaseModel):
+    options: list[ReferenceOptionResponse] = Field(default_factory=list)
+    provider_available: bool = True
+
+
 class LoginRequest(BaseModel):
     model_config = ConfigDict(extra="forbid")