feat(sdk): add before and after fields to WorktreeDiffItem schema

Extend WorktreeDiffItem with `before` and `after` string properties
across the OpenAPI spec, generated TypeScript types, and the Zod
schema in worktree-diff.ts. Both fields are marked as required in
the JSON schema definition.

packages/opencode/src/kilocode/review/worktree-diff.ts

@@ -9,6 +9,8 @@ import { Log } from "@/util/log"
 
 export namespace WorktreeDiff {
   export const Item = Snapshot.FileDiff.extend({
+    before: z.string(),
+    after: z.string(),
     tracked: z.boolean(),
     generatedLike: z.boolean(),
     summarized: z.boolean(),

packages/sdk/js/src/v2/gen/types.gen.ts

@@ -1910,6 +1910,8 @@ export type WorktreeDiffItem = {
   additions: number
   deletions: number
   status?: "added" | "deleted" | "modified"
+  before: string
+  after: string
   tracked: boolean
   generatedLike: boolean
   summarized: boolean

packages/sdk/openapi.json

@@ -15485,6 +15485,12 @@
             "type": "string",
             "enum": ["added", "deleted", "modified"]
           },
+          "before": {
+            "type": "string"
+          },
+          "after": {
+            "type": "string"
+          },
           "tracked": {
             "type": "boolean"
           },
@@ -15498,7 +15504,18 @@
             "type": "string"
           }
         },
-        "required": ["file", "patch", "additions", "deletions", "tracked", "generatedLike", "summarized", "stamp"]
+        "required": [
+          "file",
+          "patch",
+          "additions",
+          "deletions",
+          "before",
+          "after",
+          "tracked",
+          "generatedLike",
+          "summarized",
+          "stamp"
+        ]
       },
       "ProjectSummary": {
         "type": "object",