fix(hooks): use unix shell syntax for bash tool on all platforms (#1015)

The bash tool always runs in a Unix-like shell (bash/sh), even on Windows (via Git Bash, WSL, etc.), so we should always use unix export syntax instead of detecting the shell type dynamically.

Fixes #983

Fixes #889

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: justsisyphus <justsisyphus@users.noreply.github.com>
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/hooks/non-interactive-env/index.ts

@@ -1,7 +1,8 @@
 import type { PluginInput } from "@opencode-ai/plugin"
+import type { ShellType } from "../../shared"
 import { HOOK_NAME, NON_INTERACTIVE_ENV, SHELL_COMMAND_PATTERNS } from "./constants"
 import { isNonInteractive } from "./detector"
-import { log, detectShellType, buildEnvPrefix } from "../../shared"
+import { log, buildEnvPrefix } from "../../shared"
 
 export * from "./constants"
 export * from "./detector"
@@ -50,7 +51,10 @@ export function createNonInteractiveEnvHook(_ctx: PluginInput) {
         return
       }
 
-      const shellType = detectShellType()
+      // The bash tool always runs in a Unix-like shell (bash/sh), even on Windows
+      // (via Git Bash, WSL, etc.), so we always use unix export syntax.
+      // This fixes GitHub issues #983 and #889.
+      const shellType: ShellType = "unix"
       const envPrefix = buildEnvPrefix(NON_INTERACTIVE_ENV, shellType)
       output.args.command = `${envPrefix} ${command}`