add fish shell completions command

src/cli.ts

@@ -737,6 +737,70 @@ vmCmd
     console.log("✔ VM destroyed")
   })
 
+// ── sandlot completions ─────────────────────────────────────────────
+
+program
+  .command("completions")
+  .description("Output fish shell completions")
+  .action(() => {
+    process.stdout.write(`# Fish completions for sandlot
+# Install: sandlot completions > ~/.config/fish/completions/sandlot.fish
+
+complete -c sandlot -f
+
+function __sandlot_sessions
+    command sandlot list --json 2>/dev/null | string match -r '"branch":\\s*"[^"]+"' | string replace -r '.*"branch":\\s*"([^"]+)".*' '$1'
+end
+
+# Subcommands
+complete -c sandlot -n __fish_use_subcommand -a new -d "Create a new session and launch Claude"
+complete -c sandlot -n __fish_use_subcommand -a list -d "Show all active sessions"
+complete -c sandlot -n __fish_use_subcommand -a open -d "Re-enter an existing session"
+complete -c sandlot -n __fish_use_subcommand -a review -d "Launch an interactive code review"
+complete -c sandlot -n __fish_use_subcommand -a shell -d "Open a shell in the VM"
+complete -c sandlot -n __fish_use_subcommand -a close -d "Remove a worktree and clean up"
+complete -c sandlot -n __fish_use_subcommand -a merge -d "Merge a branch into main and close"
+complete -c sandlot -n __fish_use_subcommand -a save -d "Stage all changes and commit"
+complete -c sandlot -n __fish_use_subcommand -a diff -d "Show changes for a branch"
+complete -c sandlot -n __fish_use_subcommand -a show -d "Show prompt and full diff"
+complete -c sandlot -n __fish_use_subcommand -a log -d "Show commits not on main"
+complete -c sandlot -n __fish_use_subcommand -a dir -d "Print the worktree path"
+complete -c sandlot -n __fish_use_subcommand -a cleanup -d "Remove stale sessions"
+complete -c sandlot -n __fish_use_subcommand -a vm -d "Manage the sandlot VM"
+complete -c sandlot -n __fish_use_subcommand -a completions -d "Output fish shell completions"
+
+# Branch completions for commands that take a branch
+complete -c sandlot -n "__fish_seen_subcommand_from open close merge save diff show log dir review shell" -xa "(__sandlot_sessions)"
+
+# new
+complete -c sandlot -n "__fish_seen_subcommand_from new" -s p -l print -d "Run Claude non-interactively" -r
+complete -c sandlot -n "__fish_seen_subcommand_from new" -s n -l no-save -d "Skip auto-save after Claude exits"
+
+# open
+complete -c sandlot -n "__fish_seen_subcommand_from open" -s p -l print -d "Run Claude non-interactively" -r
+complete -c sandlot -n "__fish_seen_subcommand_from open" -s n -l no-save -d "Skip auto-save after Claude exits"
+
+# list
+complete -c sandlot -n "__fish_seen_subcommand_from list" -l json -d "Output as JSON"
+
+# close
+complete -c sandlot -n "__fish_seen_subcommand_from close" -s f -l force -d "Close even with unsaved changes"
+
+# review
+complete -c sandlot -n "__fish_seen_subcommand_from review" -s p -l print -d "Print review to stdout"
+
+# vm subcommands
+set -l __sandlot_vm_subs create start shell status info stop destroy
+complete -c sandlot -n "__fish_seen_subcommand_from vm; and not __fish_seen_subcommand_from \$__sandlot_vm_subs" -a create -d "Create and provision the VM"
+complete -c sandlot -n "__fish_seen_subcommand_from vm; and not __fish_seen_subcommand_from \$__sandlot_vm_subs" -a start -d "Start the VM"
+complete -c sandlot -n "__fish_seen_subcommand_from vm; and not __fish_seen_subcommand_from \$__sandlot_vm_subs" -a shell -d "Open a shell in the VM"
+complete -c sandlot -n "__fish_seen_subcommand_from vm; and not __fish_seen_subcommand_from \$__sandlot_vm_subs" -a status -d "Show VM status"
+complete -c sandlot -n "__fish_seen_subcommand_from vm; and not __fish_seen_subcommand_from \$__sandlot_vm_subs" -a info -d "Show VM system info"
+complete -c sandlot -n "__fish_seen_subcommand_from vm; and not __fish_seen_subcommand_from \$__sandlot_vm_subs" -a stop -d "Stop the VM"
+complete -c sandlot -n "__fish_seen_subcommand_from vm; and not __fish_seen_subcommand_from \$__sandlot_vm_subs" -a destroy -d "Stop and delete the VM"
+`)
+  })
+
 program.parseAsync().catch((err) => {
   console.error(`✖ ${err.message ?? err}`)
   process.exit(1)