feat: better image handling (auto resize & max size constraints) (#26401)

packages/opencode/src/config/config.ts

@@ -25,6 +25,7 @@ import { containsPath } from "../project/instance-context"
 import { zod } from "@opencode-ai/core/effect-zod"
 import { NonNegativeInt, PositiveInt, withStatics, type DeepMutable } from "@opencode-ai/core/schema"
 import { ConfigAgent } from "./agent"
+import { ConfigAttachment } from "./attachment"
 import { ConfigCommand } from "./command"
 import { ConfigFormatter } from "./formatter"
 import { ConfigLayout } from "./layout"
@@ -241,6 +242,9 @@ export const Info = Schema.Struct({
   layout: Schema.optional(ConfigLayout.Layout).annotate({ description: "@deprecated Always uses stretch layout." }),
   permission: Schema.optional(ConfigPermission.Info),
   tools: Schema.optional(Schema.Record(Schema.String, Schema.Boolean)),
+  attachment: Schema.optional(ConfigAttachment.Info).annotate({
+    description: "Attachment processing configuration, including image size limits and resizing behavior",
+  }),
   enterprise: Schema.optional(
     Schema.Struct({
       url: Schema.optional(Schema.String).annotate({ description: "Enterprise URL" }),