refactor(server): unify instance httpapi middleware routing

Unify declared instance HTTP API endpoints under typed middleware routing, including event streaming and PTY WebSocket connect handling.\n\nPreserve PTY connect compatibility by checking missing PTYs before parsing optional cursor and ticket query fields, with regression coverage.

packages/opencode/src/server/routes/instance/httpapi/middleware/instance-context.ts

@@ -1,7 +1,7 @@
 import { InstanceRef, WorkspaceRef } from "@/effect/instance-ref"
 import { InstanceStore } from "@/project/instance-store"
 import { Effect, Layer } from "effect"
-import { HttpRouter, HttpServerResponse } from "effect/unstable/http"
+import { HttpServerResponse } from "effect/unstable/http"
 import { HttpApiMiddleware } from "effect/unstable/httpapi"
 import { WorkspaceRouteContext } from "./workspace-routing"
 
@@ -41,10 +41,3 @@ export const instanceContextLayer = Layer.effect(
     return InstanceContextMiddleware.of((effect) => provideInstanceContext(effect, store))
   }),
 )
-
-export const instanceRouterMiddleware = HttpRouter.middleware()(
-  Effect.gen(function* () {
-    const store = yield* InstanceStore.Service
-    return (effect) => provideInstanceContext(effect, store)
-  }),
-)