fix(test): set OPENCODE_EXPERIMENTAL_WORKSPACES in fence header test (#26466)

packages/opencode/test/server/httpapi-instance.test.ts

@@ -14,17 +14,22 @@ import { disposeAllInstances, tmpdirScoped } from "../fixture/fixture"
 import { testEffect } from "../lib/effect"
 
 // Flip the experimental HttpApi flag so backend selection telemetry on the
-// production routes reports the right backend, and reset the database around
-// the test so per-instance state does not leak between runs. resetDatabase()
-// already calls disposeAllInstances(), so we don't repeat it.
+// production routes reports the right backend, and the experimental
+// workspaces flag so SyncEvent.run actually writes to EventSequenceTable
+// (the source of truth the fence middleware reads). Reset the database
+// around the test so per-instance state does not leak between runs.
+// resetDatabase() already calls disposeAllInstances(), so we don't repeat it.
 const testStateLayer = Layer.effectDiscard(
   Effect.gen(function* () {
     const originalHttpApi = Flag.OPENCODE_EXPERIMENTAL_HTTPAPI
+    const originalWorkspaces = Flag.OPENCODE_EXPERIMENTAL_WORKSPACES
     Flag.OPENCODE_EXPERIMENTAL_HTTPAPI = true
+    Flag.OPENCODE_EXPERIMENTAL_WORKSPACES = true
     yield* Effect.promise(() => resetDatabase())
     yield* Effect.addFinalizer(() =>
       Effect.promise(async () => {
         Flag.OPENCODE_EXPERIMENTAL_HTTPAPI = originalHttpApi
+        Flag.OPENCODE_EXPERIMENTAL_WORKSPACES = originalWorkspaces
         await resetDatabase()
       }),
     )