feat(plugin): add session request hook (#35794)

packages/core/test/plugin/fixtures/config-effect-plugin.ts

@@ -1,7 +1,7 @@
-import { define } from "@opencode-ai/plugin/v2/effect"
+import { Plugin } from "@opencode-ai/plugin/v2/effect"
 import { Effect } from "effect"
 
-export default define({
+export default Plugin.define({
   id: "config-effect-plugin",
   effect: (ctx) =>
     ctx.agent

packages/core/test/plugin/fixtures/config-promise-plugin.ts

@@ -1,6 +1,6 @@
-import { define } from "@opencode-ai/plugin/v2/promise"
+import { Plugin } from "@opencode-ai/plugin/v2"
 
-export default define({
+export default Plugin.define({
   id: "config-promise-plugin",
   setup: async (ctx) => {
     await ctx.agent.transform((agents) => {

packages/core/test/plugin/fixtures/failing-plugin.ts

@@ -1,7 +1,7 @@
-import { define } from "@opencode-ai/plugin/v2/effect"
+import { Plugin } from "@opencode-ai/plugin/v2/effect"
 import { Effect } from "effect"
 
-export default define({
+export default Plugin.define({
   id: "failing-plugin",
   effect: () => Effect.die("plugin failed"),
 })

packages/core/test/plugin/fixtures/variant-source-plugin.ts

@@ -1,8 +1,8 @@
-import { define } from "@opencode-ai/plugin/v2/effect"
+import { Plugin } from "@opencode-ai/plugin/v2/effect"
 import { ProviderV2 } from "@opencode-ai/core/provider"
 import { Effect } from "effect"
 
-export default define({
+export default Plugin.define({
   id: "variant-source",
   effect: (ctx) =>
     ctx.catalog