fix: Improve Windows compatibility for paths and shell config

- Use os.tmpdir() instead of hardcoded /tmp for cross-platform temp files
- Use os.homedir() with USERPROFILE fallback for Windows home directory
- Disable forceZsh on Windows (zsh not available by default)

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/shared/command-executor.ts

@@ -2,9 +2,14 @@ import { spawn } from "child_process"
 import { exec } from "child_process"
 import { promisify } from "util"
 import { existsSync } from "fs"
+import { homedir } from "os"
 
 const DEFAULT_ZSH_PATHS = ["/bin/zsh", "/usr/bin/zsh", "/usr/local/bin/zsh"]
 
+function getHomeDir(): string {
+  return process.env.HOME || process.env.USERPROFILE || homedir()
+}
+
 function findZshPath(customZshPath?: string): string | null {
   if (customZshPath && existsSync(customZshPath)) {
     return customZshPath
@@ -39,7 +44,7 @@ export async function executeHookCommand(
   cwd: string,
   options?: ExecuteHookOptions
 ): Promise<CommandResult> {
-  const home = process.env.HOME ?? ""
+  const home = getHomeDir()
 
   let expandedCommand = command
     .replace(/^~(?=\/|$)/g, home)