structured_patch: Support structured hunks in Write create payloads

cli/src/services/structured_patch.rs

@@ -148,9 +148,7 @@ fn build_write_create_patch(payload: &Map<String, Value>) -> PatchBuildResult {
         return skipped_build(ClaudeStructuredPatchSkipReason::UnsupportedWritePayload);
     };
 
-    if value_field(tool_response, &["originalFile", "original_file"]) != Some(&Value::Null) {
-        return skipped_build(ClaudeStructuredPatchSkipReason::UnsupportedWritePayload);
-    }
+    let structured_patch = value_field(tool_response, &["structuredPatch", "structured_patch"]);
 
     let file_path = normalize_patch_path(
         string_field(tool_input, &["file_path", "filePath"])
@@ -162,7 +160,15 @@ fn build_write_create_patch(payload: &Map<String, Value>) -> PatchBuildResult {
         return skipped_build(ClaudeStructuredPatchSkipReason::MissingFilePath);
     };
 
-    let Some(content) = string_value_field(tool_input, &["content", "newFile", "new_file"]) else {
+    if let Some(structured_patch) = structured_patch.filter(|patch| !patch.is_null()) {
+        if let Some(patch) =
+            modified_patch_from_structured_hunks(file_path.clone(), structured_patch)
+        {
+            return PatchBuildResult::Built(patch);
+        }
+    }
+
+    let Some(content) = string_value_field(tool_input, &["content"]) else {
         return skipped_build(ClaudeStructuredPatchSkipReason::MissingFileContent);
     };
 
@@ -187,29 +193,30 @@ fn build_edit_structured_patch(payload: &Map<String, Value>) -> PatchBuildResult
     }
 
     let file_path = normalize_patch_path(
-        string_field(tool_input, &["file_path", "filePath"])
-            .or_else(|| {
-                structured_patch
-                    .as_object()
-                    .and_then(|patch| string_field(patch, &["file_path", "filePath", "path"]))
-            })
-            .as_deref(),
+        string_field(tool_input, &["file_path", "filePath"]).as_deref(),
         string_field(payload, &["cwd"]).as_deref(),
     );
     let Some(file_path) = file_path else {
         return skipped_build(ClaudeStructuredPatchSkipReason::MissingFilePath);
     };
 
+    let Some(patch) = modified_patch_from_structured_hunks(file_path, structured_patch) else {
+        return skipped_build(ClaudeStructuredPatchSkipReason::UnsupportedEditPayload);
+    };
+
+    PatchBuildResult::Built(patch)
+}
+
+fn modified_patch_from_structured_hunks(
+    file_path: String,
+    structured_patch: &Value,
+) -> Option<ParsedPatch> {
     let hunks: Vec<PatchHunk> = structured_patch_hunks(structured_patch)
         .into_iter()
         .filter_map(parse_structured_patch_hunk)
         .collect();
 
-    if hunks.is_empty() {
-        return skipped_build(ClaudeStructuredPatchSkipReason::UnsupportedEditPayload);
-    }
-
-    PatchBuildResult::Built(ParsedPatch {
+    (!hunks.is_empty()).then_some(ParsedPatch {
         files: vec![PatchFileChange {
             old_path: file_path.clone(),
             new_path: file_path,

cli/src/services/structured_patch/fixtures/write_create_simple/claude-post-tool-use.json

@@ -1,12 +1,28 @@
 {
   "hook_event_name": "PostToolUse",
-  "session_id": "test-write-create-simple",
+  "session_id": "test-write-update-structured-patch",
   "tool_name": "Write",
   "tool_input": {
-    "file_path": "hunks/hello.ts",
-    "content": "function helloWorld(): void {\n  console.log(\"Hello World\");\n}\n\nhelloWorld();\n"
+    "file_path": "docs/status.md",
+    "content": "# Status\n\nThis full content fallback must not be used.\n"
   },
   "tool_response": {
-    "originalFile": null
+    "originalFile": "# Status\n\nThe old state is pending.\n",
+    "structuredPatch": {
+      "hunks": [
+        {
+          "oldStart": 1,
+          "oldCount": 3,
+          "newStart": 1,
+          "newCount": 3,
+          "lines": [
+            " # Status",
+            " ",
+            "-The old state is pending.",
+            "+The new state is complete."
+          ]
+        }
+      ]
+    }
   }
 }

cli/src/services/structured_patch/fixtures/write_create_simple/expected.patch

@@ -1,10 +1,9 @@
-diff --git a/hunks/hello.ts b/hunks/hello.ts
-new file mode 100644
---- /dev/null
-+++ b/hunks/hello.ts
-@@ -0,0 +1,5 @@
-+function helloWorld(): void {
-+  console.log("Hello World");
-+}
-+
-+helloWorld();
+Index: docs/status.md
+===================================================================
+--- a/docs/status.md
++++ b/docs/status.md
+@@ -1,3 +1,3 @@
+ # Status
+
+-The old state is pending.
++The new state is complete.