refactor(core): move v1 schemas into core (#30473)

packages/opencode/test/tool/task.test.ts

@@ -1,5 +1,5 @@
 import { afterEach, describe, expect } from "bun:test"
-import { SessionLegacy } from "@opencode-ai/core/session/legacy"
+import { SessionV1 } from "@opencode-ai/core/v1/session"
 import { Database } from "@opencode-ai/core/database/database"
 import { Effect, Exit, Fiber, Layer } from "effect"
 import { Agent } from "../../src/agent/agent"
@@ -69,7 +69,7 @@ const seed = Effect.fn("TaskToolTest.seed")(function* (title = "Pinned") {
     model: ref,
     time: { created: Date.now() },
   })
-  const assistant: SessionLegacy.Assistant = {
+  const assistant: SessionV1.Assistant = {
     id: MessageID.ascending(),
     role: "assistant",
     parentID: user.id,
@@ -99,7 +99,7 @@ function stubOps(opts?: { onPrompt?: (input: SessionPrompt.PromptInput) => void;
   }
 }
 
-function reply(input: SessionPrompt.PromptInput, text: string): SessionLegacy.WithParts {
+function reply(input: SessionPrompt.PromptInput, text: string): SessionV1.WithParts {
   const id = MessageID.ascending()
   return {
     info: {