feat(windows): cross-platform shell support and home dir expansion

- bash.rs: use cmd /C on Windows, bash -c on Unix via spawn_shell()
- agent_api.rs: fall back to USERPROFILE when HOME is not set (Windows)
- release.yml: add ci-windows job (windows-latest) for cross-platform CI

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ZhiXiao-Lin

.github/workflows/release.yml

@@ -41,6 +41,24 @@ jobs:
       - name: Tests
         run: cargo test --workspace --lib
 
+  # ───────────────────────────────────────────────
+  # Windows cross-compile check
+  # ───────────────────────────────────────────────
+  ci-windows:
+    name: CI Checks (Windows)
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Clippy (Windows)
+        run: cargo clippy --workspace -- -D warnings
+
+      - name: Tests (Windows)
+        run: cargo test --workspace --lib
+
   # ───────────────────────────────────────────────
   # Publish a3s-code-core to crates.io
   # ───────────────────────────────────────────────

core/src/agent_api.rs

@@ -515,9 +515,10 @@ impl Agent {
     pub async fn new(config_source: impl Into<String>) -> Result<Self> {
         let source = config_source.into();
 
-        // Expand leading `~/` to the user's home directory
+        // Expand leading `~/` to the user's home directory (cross-platform)
         let expanded = if let Some(rest) = source.strip_prefix("~/") {
-            if let Some(home) = std::env::var_os("HOME") {
+            let home = std::env::var_os("HOME").or_else(|| std::env::var_os("USERPROFILE"));
+            if let Some(home) = home {
                 format!("{}/{}", home.to_string_lossy(), rest)
             } else {
                 source.clone()

core/src/tools/builtin/bash.rs

@@ -12,6 +12,35 @@ const DEFAULT_TIMEOUT_MS: u64 = 120_000;
 
 pub struct BashTool;
 
+/// Spawn a shell command cross-platform.
+///
+/// - Unix: `bash -c <command>`
+/// - Windows: `cmd /C <command>` (falls back to PowerShell if cmd is unavailable)
+fn spawn_shell(
+    command: &str,
+    workspace: &std::path::Path,
+) -> std::io::Result<tokio::process::Child> {
+    #[cfg(windows)]
+    {
+        Command::new("cmd")
+            .args(["/C", command])
+            .current_dir(workspace)
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .spawn()
+    }
+    #[cfg(not(windows))]
+    {
+        Command::new("bash")
+            .arg("-c")
+            .arg(command)
+            .current_dir(workspace)
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .spawn()
+    }
+}
+
 #[async_trait]
 impl Tool for BashTool {
     fn name(&self) -> &str {
@@ -74,14 +103,8 @@ impl Tool for BashTool {
 
         let timeout_secs = timeout_ms / 1000;
 
-        let mut child = Command::new("bash")
-            .arg("-c")
-            .arg(command)
-            .current_dir(&ctx.workspace)
-            .stdout(Stdio::piped())
-            .stderr(Stdio::piped())
-            .spawn()
-            .map_err(|e| anyhow::anyhow!("Failed to spawn bash: {}", e))?;
+        let mut child = spawn_shell(command, std::path::Path::new(&ctx.workspace))
+            .map_err(|e| anyhow::anyhow!("Failed to spawn shell: {}", e))?;
 
         let (output, timed_out) =
             read_process_output(&mut child, timeout_secs, ctx.event_tx.as_ref()).await;