первый коммит

app/schemas/changeset.py

@@ -1,4 +1,5 @@
 from enum import Enum
+from typing import Literal
 from typing import Optional
 
 from pydantic import BaseModel, Field, model_validator
@@ -10,12 +11,39 @@ class ChangeOp(str, Enum):
     DELETE = "delete"
 
 
+class PatchHunk(BaseModel):
+    type: Literal["append_end", "replace_between", "replace_line_equals"]
+    new_text: str = Field(default="")
+    start_anchor: Optional[str] = None
+    end_anchor: Optional[str] = None
+    old_line: Optional[str] = None
+
+    @model_validator(mode="after")
+    def validate_hunk(self) -> "PatchHunk":
+        if self.type == "append_end":
+            if not self.new_text.strip():
+                raise ValueError("append_end requires non-empty new_text")
+            return self
+        if self.type == "replace_between":
+            if not (self.start_anchor and self.end_anchor):
+                raise ValueError("replace_between requires start_anchor and end_anchor")
+            return self
+        if self.type == "replace_line_equals":
+            if not self.old_line:
+                raise ValueError("replace_line_equals requires old_line")
+            if not self.new_text:
+                raise ValueError("replace_line_equals requires new_text")
+            return self
+        return self
+
+
 class ChangeItem(BaseModel):
     op: ChangeOp
     path: str = Field(min_length=1)
     base_hash: Optional[str] = None
     proposed_content: Optional[str] = None
     reason: str = Field(min_length=1, max_length=500)
+    hunks: list[PatchHunk] = Field(default_factory=list)
 
     @model_validator(mode="after")
     def validate_op_fields(self) -> "ChangeItem":