sandlot save <branch>

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

src/cli.ts

@@ -126,6 +126,58 @@ program
   .argument("<branch>", "branch name")
   .action(closeAction)
 
+// ── sandlot save <branch> ───────────────────────────────────────────
+
+program
+  .command("save")
+  .argument("<branch>", "branch name")
+  .description("Stage all changes and commit with an AI-generated message")
+  .action(async (branch: string) => {
+    const root = await git.repoRoot()
+    const session = await state.getSession(root, branch)
+    if (!session) {
+      console.error(`No session found for branch "${branch}".`)
+      process.exit(1)
+    }
+
+    const worktreeAbs = join(root, session.worktree)
+
+    const spin = spinner("Starting VM")
+    await vm.ensure()
+
+    spin.text = "Staging changes"
+    await vm.exec(worktreeAbs, "git add .")
+
+    const check = await vm.exec(worktreeAbs, "git diff --staged --quiet")
+    if (check.exitCode === 0) {
+      spin.fail("No changes to commit")
+      process.exit(1)
+    }
+
+    spin.text = "Generating commit message"
+    const gen = await vm.exec(
+      worktreeAbs,
+      'set -a; source ~/.env 2>/dev/null; set +a; git diff --staged | claude -p "write a short commit message summarizing these changes. output only the message, no quotes or extra text" > /tmp/sandlot_commit_msg',
+    )
+    if (gen.exitCode !== 0) {
+      spin.fail("Failed to generate commit message")
+      if (gen.stderr) console.error(gen.stderr)
+      process.exit(1)
+    }
+
+    spin.text = "Committing"
+    const commit = await vm.exec(worktreeAbs, "git commit -F /tmp/sandlot_commit_msg")
+    if (commit.exitCode !== 0) {
+      spin.fail("Commit failed")
+      if (commit.stderr) console.error(commit.stderr)
+      process.exit(1)
+    }
+
+    const { stdout: msg } = await vm.exec(worktreeAbs, "cat /tmp/sandlot_commit_msg")
+    await vm.exec(worktreeAbs, "rm -f /tmp/sandlot_commit_msg")
+    spin.succeed(`Saved: ${msg}`)
+  })
+
 // ── sandlot vm ───────────────────────────────────────────────────────
 
 const vmCmd = program.command("vm").description("Manage the sandlot VM")

src/vm.ts

@@ -89,6 +89,16 @@ export async function info(): Promise<void> {
   await proc.exited
 }
 
+/** Run a bash command in the VM at the given workdir, capturing output. */
+export async function exec(workdir: string, command: string): Promise<{ exitCode: number; stdout: string; stderr: string }> {
+  const result = await $`limactl shell --workdir=${workdir} ${VM_NAME} -- bash -c ${command}`.nothrow().quiet()
+  return {
+    exitCode: result.exitCode,
+    stdout: result.stdout.toString().trim(),
+    stderr: result.stderr.toString().trim(),
+  }
+}
+
 /** Stop the VM. */
 export async function stop(): Promise<void> {
   await $`limactl stop ${VM_NAME}`.nothrow().quiet()