fix(types): restore CI compatibility for plugin hooks and tool context

src/plugin/types.ts

@@ -2,7 +2,17 @@ import type { Plugin, ToolDefinition } from "@opencode-ai/plugin"
 
 export type PluginContext = Parameters<Plugin>[0]
 export type PluginInstance = Awaited<ReturnType<Plugin>>
-export type PluginInterface = Omit<PluginInstance, "experimental.session.compacting"> 
+
+type ChatHeadersHook = PluginInstance extends { "chat.headers"?: infer T }
+  ? T
+  : (input: unknown, output: unknown) => Promise<void>
+
+export type PluginInterface = Omit<
+  PluginInstance,
+  "experimental.session.compacting" | "chat.headers"
+> & {
+  "chat.headers"?: ChatHeadersHook
+}
 
 export type ToolsRecord = Record<string, ToolDefinition>