feat(core): add scout agent for repo research (#24149)

Co-authored-by: Dax Raad <d@ironbay.co>

packages/opencode/test/session/prompt.test.ts

@@ -15,6 +15,7 @@ import { Permission } from "../../src/permission"
 import { Plugin } from "../../src/plugin"
 import { Provider as ProviderSvc } from "@/provider/provider"
 import { Env } from "../../src/env"
+import { Git } from "../../src/git"
 import { ModelID, ProviderID } from "../../src/provider/schema"
 import { Question } from "../../src/question"
 import { Todo } from "../../src/session/todo"
@@ -178,6 +179,7 @@ function makeHttp() {
     Layer.provide(Skill.defaultLayer),
     Layer.provide(FetchHttpClient.layer),
     Layer.provide(CrossSpawnSpawner.defaultLayer),
+    Layer.provide(Git.defaultLayer),
     Layer.provide(Ripgrep.defaultLayer),
     Layer.provide(Format.defaultLayer),
     Layer.provideMerge(todo),