refactor(server): extract createApp function for server initialization

- Replace Server.App() with Server.Default() for internal server access
- Extract server app creation into Server.createApp(opts) for testability
- Move CORS whitelist from module-level variable to function parameter
- Update all tests to use Server.Default() instead of Server.App()

packages/opencode/src/cli/cmd/run.ts

@@ -667,7 +667,7 @@ export const RunCommand = cmd({
     await bootstrap(process.cwd(), async () => {
       const fetchFn = (async (input: RequestInfo | URL, init?: RequestInit) => {
         const request = new Request(input, init)
-        return Server.App().fetch(request)
+        return Server.Default().fetch(request)
       }) as typeof globalThis.fetch
       const sdk = createOpencodeClient({ baseUrl: "http://opencode.internal", fetch: fetchFn })
       await execute(sdk)

packages/opencode/src/cli/cmd/tui/worker.ts

@@ -54,7 +54,7 @@ const startEventStream = (input: { directory: string; workspaceID?: string }) =>
     const request = new Request(input, init)
     const auth = getAuthorizationHeader()
     if (auth) request.headers.set("Authorization", auth)
-    return Server.App().fetch(request)
+    return Server.Default().fetch(request)
   }) as typeof globalThis.fetch
 
   const sdk = createOpencodeClient({
@@ -110,7 +110,7 @@ export const rpc = {
       headers,
       body: input.body,
     })
-    const response = await Server.App().fetch(request)
+    const response = await Server.Default().fetch(request)
     const body = await response.text()
     return {
       status: response.status,

packages/opencode/src/plugin/index.ts

@@ -25,8 +25,7 @@ export namespace Plugin {
     const client = createOpencodeClient({
       baseUrl: "http://localhost:4096",
       directory: Instance.directory,
-      // @ts-ignore - fetch type incompatibility
+      fetch: async (...args) => Server.Default().fetch(...args),
-      fetch: async (...args) => Server.App().fetch(...args),
     })
     const config = await Config.get()
     const hooks: Hooks[] = []
@@ -35,7 +34,9 @@ export namespace Plugin {
       project: Instance.project,
       worktree: Instance.worktree,
       directory: Instance.directory,
-      serverUrl: Server.url(),
+      get serverUrl(): URL {
+        throw new Error("Server URL is no longer supported in plugins")
+      },
       $: Bun.$,
     }
 

packages/opencode/test/server/project-init-git.test.ts

@@ -19,7 +19,7 @@ afterEach(async () => {
 describe("project.initGit endpoint", () => {
   test("initializes git and reloads immediately", async () => {
     await using tmp = await tmpdir()
-    const app = Server.App()
+    const app = Server.Default()
     const seen: { directory?: string; payload: { type: string } }[] = []
     const fn = (evt: { directory?: string; payload: { type: string } }) => {
       seen.push(evt)
@@ -75,7 +75,7 @@ describe("project.initGit endpoint", () => {
 
   test("does not reload when the project is already git", async () => {
     await using tmp = await tmpdir({ git: true })
-    const app = Server.App()
+    const app = Server.Default()
     const seen: { directory?: string; payload: { type: string } }[] = []
     const fn = (evt: { directory?: string; payload: { type: string } }) => {
       seen.push(evt)

packages/opencode/test/server/session-select.test.ts

@@ -17,7 +17,7 @@ describe("tui.selectSession endpoint", () => {
         const session = await Session.create({})
 
         // #when
-        const app = Server.App()
+        const app = Server.Default()
         const response = await app.request("/tui/select-session", {
           method: "POST",
           headers: { "Content-Type": "application/json" },
@@ -42,7 +42,7 @@ describe("tui.selectSession endpoint", () => {
         const nonExistentSessionID = "ses_nonexistent123"
 
         // #when
-        const app = Server.App()
+        const app = Server.Default()
         const response = await app.request("/tui/select-session", {
           method: "POST",
           headers: { "Content-Type": "application/json" },
@@ -63,7 +63,7 @@ describe("tui.selectSession endpoint", () => {
         const invalidSessionID = "invalid_session_id"
 
         // #when
-        const app = Server.App()
+        const app = Server.Default()
         const response = await app.request("/tui/select-session", {
           method: "POST",
           headers: { "Content-Type": "application/json" },