v1.0.0 — first release

Bump VERSION to 1.0.0 and cut the first tagged release of vpp-maglev.

Also in this commit:

- maglevc: MAGLEV_SERVER env var as an alternative to the --server
  flag, matching the MAGLEV_CONFIG / MAGLEV_GRPC_ADDR convention on
  the other binaries. The flag takes precedence when both are set.
- Rename cmd/maglevd -> cmd/server and cmd/maglevc -> cmd/client so
  the source directory names are decoupled from binary names (the
  frontend and tester commands already followed this convention).
  Build outputs and the Debian packages are unchanged.

cmd/client/shell.go

@@ -0,0 +1,123 @@
+// Copyright (c) 2026, Pim van Pelt <pim@ipng.ch>
+
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/chzyer/readline"
+
+	"git.ipng.ch/ipng/vpp-maglev/internal/grpcapi"
+)
+
+// errQuit is a sentinel returned by runQuit to exit the REPL.
+var errQuit = errors.New("quit")
+
+// runShell runs the interactive REPL until the user types quit/exit or EOF.
+func runShell(ctx context.Context, client grpcapi.MaglevClient) error {
+	root := buildTree()
+
+	comp := &Completer{root: root, client: client}
+	ql := &questionListener{root: root, client: client}
+
+	cfg := &readline.Config{
+		Prompt:          "maglev> ",
+		AutoComplete:    comp,
+		InterruptPrompt: "^C",
+		EOFPrompt:       "exit",
+		Listener:        ql,
+	}
+	rl, err := readline.NewEx(cfg)
+	if err != nil {
+		return fmt.Errorf("readline init: %w", err)
+	}
+	ql.rl = rl
+	defer func() { _ = rl.Close() }()
+
+	for {
+		line, err := rl.Readline()
+		if err == readline.ErrInterrupt {
+			continue
+		}
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+
+		tokens := splitTokens(line)
+		if len(tokens) == 0 {
+			continue
+		}
+
+		if err := dispatch(ctx, root, client, tokens); err != nil {
+			if errors.Is(err, errQuit) {
+				return nil
+			}
+			_, _ = fmt.Fprintf(rl.Stderr(), "%s\n", formatError(err))
+		}
+	}
+}
+
+// dispatch walks the tree and executes the matched command.
+func dispatch(ctx context.Context, root *Node, client grpcapi.MaglevClient, tokens []string) error {
+	node, args, remaining := Walk(root, tokens)
+
+	if len(remaining) > 0 {
+		// One or more tokens couldn't be matched. Report the first
+		// offending token with the consumed prefix for context; don't
+		// dump the full command tree prefixed with garbage, which is
+		// what the previous code did and what prompted this fix.
+		consumed := tokens[:len(tokens)-len(remaining)]
+		return unknownCommandError(consumed, remaining[0])
+	}
+
+	if node.Run == nil {
+		showHelpAt(node, strings.Join(tokens, " "))
+		return nil
+	}
+
+	return node.Run(ctx, client, args)
+}
+
+// unknownCommandError builds the error returned by dispatch when the
+// tree walk couldn't consume the full token list. The format differs
+// slightly depending on whether any tokens were consumed, so the
+// message always points at the first unknown token and its context.
+func unknownCommandError(consumed []string, bad string) error {
+	if len(consumed) == 0 {
+		return fmt.Errorf("unknown command: %s", bad)
+	}
+	return fmt.Errorf("unknown subcommand %q after %q", bad, strings.Join(consumed, " "))
+}
+
+// showHelpAt prints the reachable leaves below node, each displayed
+// with the given prefix. Split from dispatch so the caller can decide
+// which node to anchor the help at without re-walking the tree.
+func showHelpAt(node *Node, prefix string) {
+	lines := expandPaths(node, prefix, make(map[*Node]bool))
+
+	maxLen := 0
+	for _, l := range lines {
+		if len(l.path) > maxLen {
+			maxLen = len(l.path)
+		}
+	}
+
+	if len(lines) == 0 {
+		fmt.Println("  <no completions>")
+		return
+	}
+	for _, l := range lines {
+		if l.help != "" {
+			fmt.Printf("%-*s  %s\n", maxLen+2, l.path, l.help)
+		} else {
+			fmt.Printf("%s\n", l.path)
+		}
+	}
+}