Convert LoadInput.init to Effect + extract InstanceBootstrap as a Service (#25376)

packages/opencode/src/project/instance-context.ts

@@ -1,4 +1,5 @@
 import { LocalContext } from "@/util/local-context"
+import { AppFileSystem } from "@opencode-ai/core/filesystem"
 import type * as Project from "./project"
 
 export interface InstanceContext {
@@ -8,3 +9,16 @@ export interface InstanceContext {
 }
 
 export const context = LocalContext.create<InstanceContext>("instance")
+
+/**
+ * Check if a path is within the project boundary.
+ * Returns true if path is inside ctx.directory OR ctx.worktree.
+ * Paths within the worktree but outside the working directory should not trigger external_directory permission.
+ */
+export function containsPath(filepath: string, ctx: InstanceContext): boolean {
+  if (AppFileSystem.contains(ctx.directory, filepath)) return true
+  // Non-git projects set worktree to "/" which would match ANY absolute path.
+  // Skip worktree check in this case to preserve external_directory permissions.
+  if (ctx.worktree === "/") return false
+  return AppFileSystem.contains(ctx.worktree, filepath)
+}