feat: add git-backed session review modes (#17961)

packages/opencode/src/server/server.ts

@@ -41,6 +41,7 @@ import { websocket } from "hono/bun"
 import { HTTPException } from "hono/http-exception"
 import { errors } from "./error"
 import { Filesystem } from "@/util/filesystem"
+import { Snapshot } from "@/snapshot"
 import { QuestionRoutes } from "./routes/question"
 import { PermissionRoutes } from "./routes/permission"
 import { GlobalRoutes } from "./routes/global"
@@ -332,10 +333,39 @@ export namespace Server {
           },
         }),
         async (c) => {
-          const branch = await runPromiseInstance(Vcs.Service.use((s) => s.branch()))
-          return c.json({
-            branch,
-          })
+          const [branch, default_branch] = await Promise.all([
+            runPromiseInstance(Vcs.Service.use((s) => s.branch())),
+            runPromiseInstance(Vcs.Service.use((s) => s.defaultBranch())),
+          ])
+          return c.json({ branch, default_branch })
+        },
+      )
+      .get(
+        "/vcs/diff",
+        describeRoute({
+          summary: "Get VCS diff",
+          description: "Retrieve the current git diff for the working tree or against the default branch.",
+          operationId: "vcs.diff",
+          responses: {
+            200: {
+              description: "VCS diff",
+              content: {
+                "application/json": {
+                  schema: resolver(Snapshot.FileDiff.array()),
+                },
+              },
+            },
+          },
+        }),
+        validator(
+          "query",
+          z.object({
+            mode: Vcs.Mode,
+          }),
+        ),
+        async (c) => {
+          const mode = c.req.valid("query").mode
+          return c.json(await runPromiseInstance(Vcs.Service.use((s) => s.diff(mode))))
         },
       )
       .get(