refactor(core): consolidate tool architecture

packages/plugin/src/effect/session.ts

@@ -0,0 +1,27 @@
+import type { SessionApi } from "@opencode-ai/client/effect/api"
+import type { Message, SystemPart } from "@opencode-ai/ai"
+import type { Agent } from "@opencode-ai/schema/agent"
+import type { Model } from "@opencode-ai/schema/model"
+import type { Session } from "@opencode-ai/schema/session"
+import type { JsonSchema } from "effect"
+import type { Hooks } from "./registration.js"
+
+export interface SessionContext {
+  readonly sessionID: Session.ID
+  readonly agent: Agent.ID
+  readonly model: Model.Ref
+  system: Array<SystemPart>
+  messages: Array<Message>
+  tools: Record<string, { description: string; input: JsonSchema.JsonSchema }>
+}
+
+export interface SessionHooks {
+  readonly context: SessionContext
+}
+
+export type SessionDomain = Pick<
+  SessionApi<unknown>,
+  "create" | "get" | "prompt" | "generate" | "command" | "synthetic" | "interrupt"
+> & {
+  readonly hook: Hooks<SessionHooks>
+}