feat: interactive CLI wizard for zero-config onboarding (#350)

Implement an interactive TUI setup wizard that launches automatically when
no config file is found. Guides users through provider, model, and channel
setup in ~1 minute.

Features:
- Auto-detect environment (Ollama, network, NPU hardware)
- Arrow-key interactive menus with vim j/k support
- Masked API key input via readline
- Dynamic model list fetching from provider APIs:
  OpenRouter, OpenAI, Anthropic, Gemini, Groq, Zhipu, Ollama/vLLM
- Searchable model selector (type-to-filter) for large lists (>20 models)
- Smart defaults based on detected environment
- Progress bar and info boxes for guided experience
- Graceful fallback for non-interactive terminals
- Generates valid config.json and offers to auto-start the agent

Closes #350

cmd/picoclaw/main.go

@@ -121,6 +121,9 @@ func copyDirectory(src, dst string) error {
 
 func main() {
 	if len(os.Args) < 2 {
+		if maybeRunZeroConfigWizard() {
+			return
+		}
 		printHelp()
 		os.Exit(1)
 	}

cmd/picoclaw/wizard_test.go

@@ -0,0 +1,133 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestDefaultConfigSearchPaths(t *testing.T) {
+	home := "/tmp/home-test"
+	paths := defaultConfigSearchPaths(home)
+	if len(paths) < 4 {
+		t.Fatalf("expected multiple config search paths, got %d", len(paths))
+	}
+
+	hasHomeConfig := false
+	for _, p := range paths {
+		if p == filepath.Join(home, ".picoclaw", "config.json") {
+			hasHomeConfig = true
+			break
+		}
+	}
+	if !hasHomeConfig {
+		t.Fatal("expected home config path in defaultConfigSearchPaths")
+	}
+}
+
+func TestHasConfigInPaths(t *testing.T) {
+	dir := t.TempDir()
+	missing := filepath.Join(dir, "missing.json")
+	if hasConfigInPaths([]string{missing}) {
+		t.Fatal("expected false when config does not exist")
+	}
+
+	cfgPath := filepath.Join(dir, "config.json")
+	if err := os.WriteFile(cfgPath, []byte(`{"ok":true}`), 0644); err != nil {
+		t.Fatalf("failed to write temp config: %v", err)
+	}
+
+	if !hasConfigInPaths([]string{missing, cfgPath}) {
+		t.Fatal("expected true when one path exists")
+	}
+}
+
+func TestParseCSV(t *testing.T) {
+	items := parseCSV(" 123, ,abc,  xyz ")
+	if len(items) != 3 {
+		t.Fatalf("expected 3 items, got %d", len(items))
+	}
+	if items[0] != "123" || items[1] != "abc" || items[2] != "xyz" {
+		t.Fatalf("unexpected parse result: %#v", items)
+	}
+}
+
+func TestVisibleLen(t *testing.T) {
+	if got := visibleLen("hello"); got != 5 {
+		t.Fatalf("expected 5, got %d", got)
+	}
+	// ANSI escape codes should not count
+	if got := visibleLen("\033[31mred\033[0m"); got != 3 {
+		t.Fatalf("expected 3 for colored string, got %d", got)
+	}
+	if got := visibleLen(""); got != 0 {
+		t.Fatalf("expected 0 for empty string, got %d", got)
+	}
+}
+
+func TestDetectEnvironment(t *testing.T) {
+	env := detectEnvironment()
+	// Just verify it doesn't panic and returns a struct
+	_ = env.OllamaFound
+	_ = env.NetworkOnline
+	_ = env.NPUDetected
+	_ = env.NPUDevice
+}
+
+func TestParseOpenAIModels(t *testing.T) {
+	data := []byte(`{"data":[{"id":"gpt-4o"},{"id":"gpt-4o-mini"},{"id":"gpt-3.5-turbo"}]}`)
+	models, err := parseOpenAIModels(data)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(models) != 3 {
+		t.Fatalf("expected 3 models, got %d", len(models))
+	}
+	// Should be sorted
+	if models[0] != "gpt-3.5-turbo" {
+		t.Fatalf("expected sorted first model gpt-3.5-turbo, got %s", models[0])
+	}
+}
+
+func TestParseOpenAIModelsEmpty(t *testing.T) {
+	data := []byte(`{"data":[]}`)
+	models, err := parseOpenAIModels(data)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(models) != 0 {
+		t.Fatalf("expected 0 models, got %d", len(models))
+	}
+}
+
+func TestParseGeminiModels(t *testing.T) {
+	data := []byte(`{"models":[{"name":"models/gemini-2.5-flash"},{"name":"models/gemini-pro"}]}`)
+	models, err := parseGeminiModels(data)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(models) != 2 {
+		t.Fatalf("expected 2 models, got %d", len(models))
+	}
+	// Should strip "models/" prefix and be sorted
+	if models[0] != "gemini-2.5-flash" {
+		t.Fatalf("expected gemini-2.5-flash, got %s", models[0])
+	}
+	if models[1] != "gemini-pro" {
+		t.Fatalf("expected gemini-pro, got %s", models[1])
+	}
+}
+
+func TestParseOpenAIModelsInvalidJSON(t *testing.T) {
+	_, err := parseOpenAIModels([]byte(`not json`))
+	if err == nil {
+		t.Fatal("expected error for invalid JSON")
+	}
+}
+
+func TestParseGeminiModelsInvalidJSON(t *testing.T) {
+	_, err := parseGeminiModels([]byte(`{broken`))
+	if err == nil {
+		t.Fatal("expected error for invalid JSON")
+	}
+}