Added comment functionality

backend/src/models.py

@@ -309,3 +309,45 @@ class RequirementSearchResult(BaseModel):
 
     class Config:
         from_attributes = True
+
+
+# Comment schemas
+class CommentReplyResponse(BaseModel):
+    """Response schema for a comment reply."""
+    id: int
+    reply_text: str
+    created_at: Optional[datetime] = None
+    updated_at: Optional[datetime] = None
+    author_id: Optional[int] = None
+    author_username: Optional[str] = None
+    author_full_name: Optional[str] = None
+    author_role: Optional[str] = None
+
+    class Config:
+        from_attributes = True
+
+
+class CommentResponse(BaseModel):
+    """Response schema for a comment with its replies."""
+    id: int
+    comment_text: str
+    created_at: Optional[datetime] = None
+    updated_at: Optional[datetime] = None
+    author_id: Optional[int] = None
+    author_username: Optional[str] = None
+    author_full_name: Optional[str] = None
+    author_role: Optional[str] = None
+    replies: List[CommentReplyResponse] = []
+
+    class Config:
+        from_attributes = True
+
+
+class CommentCreateRequest(BaseModel):
+    """Request schema for creating a comment."""
+    comment_text: str
+
+
+class ReplyCreateRequest(BaseModel):
+    """Request schema for creating a reply."""
+    reply_text: str