refactor(core): move database schema ownership (#29068)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

packages/opencode/src/session/prompt/reference.ts

@@ -1,4 +1,5 @@
 import { Option, Schema } from "effect"
+import { SessionLegacy } from "@opencode-ai/core/session/legacy"
 import { MessageV2 } from "../message-v2"
 import { Reference } from "@/reference/reference"
 
@@ -33,7 +34,7 @@ export function referenceTextPart(input: {
   target?: string
   targetPath?: string
   problem?: string
-}): MessageV2.TextPartInput {
+}): SessionLegacy.TextPartInput {
   const metadata: ReferencePromptMetadata = {
     name: input.reference.name,
     kind: input.reference.kind,