feat: auto-derive branch name from prompt when spaces detected

src/cli.ts

@@ -20,10 +20,21 @@ program.name("sandlot").description("Branch-based development with git worktrees
 
 program
   .command("new")
-  .argument("<branch>", "branch name")
+  .argument("<branch>", "branch name or prompt (if it contains spaces)")
   .argument("[prompt]", "initial prompt for Claude")
   .description("Create a new session and launch Claude")
   .action(async (branch: string, prompt?: string) => {
+    // If the "branch" contains spaces, it's actually a prompt — derive the branch name
+    if (branch.includes(" ")) {
+      prompt = branch
+      branch = branch
+        .toLowerCase()
+        .replace(/[^a-z0-9\s-]/g, "")
+        .trim()
+        .replace(/\s+/g, "-")
+        .slice(0, 20)
+        .replace(/-$/, "")
+    }
     const root = await git.repoRoot()
     const worktreeAbs = join(homedir(), '.sandlot', basename(root), branch)