No canonical snake_case/camelCase serialization policy

backend/app/models/response.py

@@ -96,7 +96,27 @@ from pydantic import BaseModel, ConfigDict, Field
 T = TypeVar("T")
 
 
-class PaginatedListResponse(BaseModel, Generic[T]):
+class BanGuiBaseModel(BaseModel):
+    """Project-wide Pydantic base model.
+
+    Enforces the canonical **snake_case** API field naming policy:
+    all JSON wire-format field names use ``snake_case`` on both the backend
+    (Python) and the frontend (TypeScript interfaces).  No ``alias_generator``
+    is applied — field names are serialized exactly as written.
+
+    Rules:
+    - Every model in ``app/models/`` must inherit from this class.
+    - Field names must be ``snake_case`` in Python *and* in the JSON payload.
+    - The corresponding TypeScript interface fields must also be ``snake_case``.
+    - Never add a ``camelCase`` alias generator to individual models — any
+      serialization change must go through this base class so all models
+      update at once.
+    """
+
+    model_config = ConfigDict(strict=True)
+
+
+class PaginatedListResponse(BanGuiBaseModel, Generic[T]):
     """Standardized paginated list response.
 
     Use this as a base for all endpoints that return paginated collections.
@@ -123,15 +143,13 @@ class PaginatedListResponse(BaseModel, Generic[T]):
         ```
     """
 
-    model_config = ConfigDict(strict=True)
-
     items: list[T] = Field(default_factory=list, description="Data items for the current page.")
     total: int = Field(..., ge=0, description="Total number of items matching the query.")
     page: int = Field(..., ge=1, description="Current page number (1-based).")
     page_size: int = Field(..., ge=1, description="Number of items per page.")
 
 
-class CollectionResponse(BaseModel, Generic[T]):
+class CollectionResponse(BanGuiBaseModel, Generic[T]):
     """Standardized non-paginated collection response.
 
     Use this for endpoints that return a collection without pagination support.
@@ -154,13 +172,11 @@ class CollectionResponse(BaseModel, Generic[T]):
         ```
     """
 
-    model_config = ConfigDict(strict=True)
-
     items: list[T] = Field(default_factory=list, description="Collection items.")
     total: int = Field(..., ge=0, description="Total number of items.")
 
 
-class CommandResponse(BaseModel):
+class CommandResponse(BanGuiBaseModel):
     """Standardized command/action result response.
 
     Use this for endpoints that execute commands (start, stop, reload, ban, unban, etc.).
@@ -184,8 +200,6 @@ class CommandResponse(BaseModel):
         ```
     """
 
-    model_config = ConfigDict(strict=True)
-
     message: str = Field(..., description="Human-readable result or error message.")
     success: bool = Field(
         default=True,