fix(auto-updater): handle bun.lockb and add workspace validation

- Support binary bun.lockb format by deleting entire file (cannot parse)
- Add workspace check: verify package.json exists before bun install
- Quote paths in error messages for Windows/paths with spaces

src/cli/config-manager/bun-install.test.ts

@@ -1,4 +1,5 @@
-import { beforeEach, afterEach, describe, expect, it, mock, spyOn } from "bun:test"
+import { beforeEach, afterEach, describe, expect, it, spyOn } from "bun:test"
+import * as fs from "node:fs"
 import * as dataPath from "../../shared/data-path"
 import * as logger from "../../shared/logger"
 import * as spawnHelpers from "../../shared/spawn-with-windows-hide"
@@ -8,6 +9,7 @@ describe("runBunInstallWithDetails", () => {
   let getOpenCodeCacheDirSpy: ReturnType<typeof spyOn>
   let logSpy: ReturnType<typeof spyOn>
   let spawnWithWindowsHideSpy: ReturnType<typeof spyOn>
+  let existsSyncSpy: ReturnType<typeof spyOn>
 
   beforeEach(() => {
     getOpenCodeCacheDirSpy = spyOn(dataPath, "getOpenCodeCacheDir").mockReturnValue("/tmp/opencode-cache")
@@ -15,14 +17,16 @@ describe("runBunInstallWithDetails", () => {
     spawnWithWindowsHideSpy = spyOn(spawnHelpers, "spawnWithWindowsHide").mockReturnValue({
       exited: Promise.resolve(0),
       exitCode: 0,
-      kill: mock(() => {}),
+      kill: () => {},
     } as ReturnType<typeof spawnHelpers.spawnWithWindowsHide>)
+    existsSyncSpy = spyOn(fs, "existsSync").mockReturnValue(true)
   })
 
   afterEach(() => {
     getOpenCodeCacheDirSpy.mockRestore()
     logSpy.mockRestore()
     spawnWithWindowsHideSpy.mockRestore()
+    existsSyncSpy.mockRestore()
   })
 
   it("runs bun install in the OpenCode cache directory", async () => {

src/cli/config-manager/bun-install.ts

@@ -1,3 +1,4 @@
+import { existsSync } from "node:fs"
 import { getOpenCodeCacheDir } from "../../shared/data-path"
 import { log } from "../../shared/logger"
 import { spawnWithWindowsHide } from "../../shared/spawn-with-windows-hide"
@@ -18,6 +19,14 @@ export async function runBunInstall(): Promise<boolean> {
 
 export async function runBunInstallWithDetails(): Promise<BunInstallResult> {
   const cacheDir = getOpenCodeCacheDir()
+  const packageJsonPath = `${cacheDir}/package.json`
+
+  if (!existsSync(packageJsonPath)) {
+    return {
+      success: false,
+      error: `Workspace not initialized: ${packageJsonPath} not found. OpenCode should create this on first run.`,
+    }
+  }
 
   try {
     const proc = spawnWithWindowsHide(["bun", "install"], {
@@ -43,7 +52,7 @@ export async function runBunInstallWithDetails(): Promise<BunInstallResult> {
       return {
         success: false,
         timedOut: true,
-        error: `bun install timed out after ${BUN_INSTALL_TIMEOUT_SECONDS} seconds. Try running manually: cd ${cacheDir} && bun i`,
+        error: `bun install timed out after ${BUN_INSTALL_TIMEOUT_SECONDS} seconds. Try running manually: cd "${cacheDir}" && bun i`,
       }
     }