fix(doctor): address review — rename shadowing var, align missing-binary message

- Rename the local `runtime` (was shadowing the stdlib `runtime` package used
  elsewhere in doctor.go) to `runtimeVersion`.
- Align the unresolvable-binary FAIL message's remediation with the npm wrapper
  (reinstall, or build from source: <repo url>) so both missing-binary paths
  give consistent guidance.

Addresses CodeRabbit review on #405.

README.md

@@ -142,13 +142,6 @@ the key in the wizard:
 export OPENAI_API_KEY=sk-...
 export ANTHROPIC_API_KEY=...
 export GEMINI_API_KEY=...
-export LONGCAT_API_KEY=...
-```
-
-To configure Meituan LongCat (LongCat-2.0) directly, run:
-
-```bash
-zero providers setup longcat --set-active
 ```
 
 For local models, run Ollama or LM Studio and then use `zero setup` or

internal/cli/observability.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"runtime"
 	"strconv"
 	"strings"
 
@@ -65,7 +66,7 @@ func runDoctor(args []string, stdout io.Writer, stderr io.Writer, deps appDeps)
 
 	report := doctor.Run(doctor.Options{
 		Now:            deps.now,
-		Runtime:        "go",
+		Runtime:        runtime.Version(),
 		UserConfig:     userConfig,
 		ProjectConfig:  projectConfig,
 		Provider:       provider,

internal/cli/provider_catalog_onboarding_test.go

@@ -18,7 +18,6 @@ func TestProviderCatalogRuntimeProvidersShowOnboardingSetupHints(t *testing.T) {
 	}{
 		{id: "openai", name: "OpenAI", transport: "openai", defaultModel: "gpt-4.1"},
 		{id: "groq", name: "Groq", transport: "openai-compatible", defaultModel: "llama-3.3-70b-versatile"},
-		{id: "longcat", name: "LongCat", transport: "openai-compatible", defaultModel: "LongCat-2.0"},
 		{id: "ollama-cloud", name: "Ollama Cloud", transport: "openai-compatible", defaultModel: "qwen3-coder:480b"},
 		{id: "ollama", name: "Ollama Local", transport: "openai-compatible", defaultModel: "llama3.1"},
 	}
@@ -47,21 +46,6 @@ func TestProviderCatalogRuntimeProvidersShowOnboardingSetupHints(t *testing.T) {
 	}
 }
 
-func TestProviderCatalogLongCatRequiresAPIKey(t *testing.T) {
-	output := runProviderCatalogOnboarding(t)
-	block := providerCatalogOnboardingBlock(t, output, "longcat")
-
-	for _, want := range []string{
-		"requiresAuth=true",
-		"authEnvVars=LONGCAT_API_KEY",
-		"setup: zero providers setup longcat --set-active",
-	} {
-		if !strings.Contains(block, want) {
-			t.Fatalf("expected LongCat catalog block to contain %q, got:\n%s", want, block)
-		}
-	}
-}
-
 func TestProviderCatalogOllamaCloudRequiresAPIKey(t *testing.T) {
 	output := runProviderCatalogOnboarding(t)
 	block := providerCatalogOnboardingBlock(t, output, "ollama-cloud")

internal/doctor/doctor.go

@@ -57,6 +57,11 @@ type Options struct {
 	// LSP-server checks. Nil means exec.LookPath; tests inject a stub so the
 	// checks are deterministic regardless of the host's installed tooling.
 	LookupExecutable func(string) (string, error)
+	// Executable resolves the running Zero binary's path (nil => os.Executable)
+	// and StatExecutable stats it (nil => os.Stat). Injected so the native-binary
+	// runtime check is testable without depending on a real on-disk layout.
+	Executable     func() (string, error)
+	StatExecutable func(string) (os.FileInfo, error)
 }
 
 func Run(options Options) Report {
@@ -65,7 +70,7 @@ func Run(options Options) Report {
 		now = time.Now
 	}
 	checks := []Check{
-		runtimeCheck(options.Runtime),
+		runtimeCheck(options),
 		configFilesCheck(options.UserConfig, options.ProjectConfig),
 		configValidationCheck(options.UserConfig, options.ProjectConfig),
 	}
@@ -114,12 +119,48 @@ func Format(report Report) string {
 	return strings.Join(lines, "\n")
 }
 
-func runtimeCheck(runtime string) Check {
-	runtime = strings.TrimSpace(runtime)
-	if runtime == "" {
-		runtime = "go"
+// runtimeCheck verifies the running Zero native binary is actually present and
+// runnable, and reports its resolved path — instead of the former hardcoded
+// always-pass, which claimed "Go runtime is available" while checking nothing
+// (#405). doctor executes INSIDE the native binary, so this only fails if
+// os.Executable can't resolve or the running file has vanished; the missing-
+// binary-at-install case is caught earlier by the npm wrapper, which refuses to
+// launch without the platform binary. Surfacing the binary PATH is the useful
+// part: it lets a user see which binary answered (e.g. an npm-installed one vs a
+// stale/shadowing copy on PATH) rather than a meaningless green.
+func runtimeCheck(options Options) Check {
+	runtimeVersion := strings.TrimSpace(options.Runtime)
+	if runtimeVersion == "" {
+		runtimeVersion = "go"
 	}
-	return check("runtime.go", "Go runtime", StatusPass, fmt.Sprintf("Zero Go runtime is available (%s).", runtime), map[string]any{"runtime": runtime})
+	details := map[string]any{"runtime": runtimeVersion}
+
+	executable := options.Executable
+	if executable == nil {
+		executable = os.Executable
+	}
+	path, err := executable()
+	if err != nil {
+		return check("runtime.go", "Zero native binary", StatusFail,
+			"Could not resolve the running Zero binary: "+err.Error(), details)
+	}
+	details["binaryPath"] = path
+
+	stat := options.StatExecutable
+	if stat == nil {
+		stat = os.Stat
+	}
+	info, err := stat(path)
+	if err != nil {
+		return check("runtime.go", "Zero native binary", StatusFail,
+			fmt.Sprintf("The running Zero binary is not accessible at %s: %s. Reinstall the zero package, or build from source: https://github.com/Gitlawb/zero", path, err.Error()), details)
+	}
+	if info.IsDir() {
+		return check("runtime.go", "Zero native binary", StatusFail,
+			fmt.Sprintf("The resolved Zero binary path %s is a directory, not an executable.", path), details)
+	}
+	return check("runtime.go", "Zero native binary", StatusPass,
+		fmt.Sprintf("Zero native binary is present and runnable at %s (%s).", path, runtimeVersion), details)
 }
 
 func configFilesCheck(userPath string, projectPath string) Check {

internal/doctor/runtime_check_test.go

@@ -0,0 +1,88 @@
+package doctor
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"strings"
+	"testing"
+	"time"
+)
+
+// fakeFileInfo is a minimal os.FileInfo for the runtime-check stat injection.
+type fakeFileInfo struct{ dir bool }
+
+func (f fakeFileInfo) Name() string       { return "zero" }
+func (f fakeFileInfo) Size() int64        { return 1 }
+func (f fakeFileInfo) Mode() fs.FileMode  { return 0o755 }
+func (f fakeFileInfo) ModTime() time.Time { return time.Unix(0, 0) }
+func (f fakeFileInfo) IsDir() bool        { return f.dir }
+func (f fakeFileInfo) Sys() any           { return nil }
+
+func runtimeCheckFor(t *testing.T, exe func() (string, error), stat func(string) (os.FileInfo, error)) Check {
+	t.Helper()
+	return runtimeCheck(Options{Runtime: "go1.26", Executable: exe, StatExecutable: stat})
+}
+
+// A present, runnable binary passes AND reports its resolved path — the check is
+// no longer a hardcoded green; it names which binary answered.
+func TestRuntimeCheckPassesAndReportsBinaryPath(t *testing.T) {
+	c := runtimeCheckFor(t,
+		func() (string, error) { return "/opt/homebrew/lib/node_modules/@gitlawb/zero/zero", nil },
+		func(string) (os.FileInfo, error) { return fakeFileInfo{}, nil })
+	if c.Status != StatusPass {
+		t.Fatalf("status = %s, want pass", c.Status)
+	}
+	if c.Details["binaryPath"] != "/opt/homebrew/lib/node_modules/@gitlawb/zero/zero" {
+		t.Fatalf("binaryPath = %v, want the resolved path in details", c.Details["binaryPath"])
+	}
+	if !strings.Contains(c.Message, "/opt/homebrew/lib/node_modules/@gitlawb/zero/zero") {
+		t.Fatalf("message should surface the binary path, got %q", c.Message)
+	}
+}
+
+// The vanished-binary case FAILS loudly instead of the old unconditional pass —
+// this is the #405 regression: a broken runtime no longer gets a green check.
+func TestRuntimeCheckFailsWhenBinaryMissing(t *testing.T) {
+	c := runtimeCheckFor(t,
+		func() (string, error) { return "/path/to/zero", nil },
+		func(string) (os.FileInfo, error) { return nil, os.ErrNotExist })
+	if c.Status != StatusFail {
+		t.Fatalf("#405: a missing/inaccessible binary must FAIL, got %s (%q)", c.Status, c.Message)
+	}
+	if !strings.Contains(c.Message, "/path/to/zero") {
+		t.Fatalf("failure message should name the path, got %q", c.Message)
+	}
+}
+
+// os.Executable resolution failure fails loudly too.
+func TestRuntimeCheckFailsWhenExecutableUnresolvable(t *testing.T) {
+	c := runtimeCheckFor(t,
+		func() (string, error) { return "", errors.New("no executable path") },
+		func(string) (os.FileInfo, error) { return fakeFileInfo{}, nil })
+	if c.Status != StatusFail {
+		t.Fatalf("unresolvable executable must FAIL, got %s", c.Status)
+	}
+}
+
+// A path that resolves to a directory is not a runnable binary → FAIL.
+func TestRuntimeCheckFailsWhenPathIsDirectory(t *testing.T) {
+	c := runtimeCheckFor(t,
+		func() (string, error) { return "/some/dir", nil },
+		func(string) (os.FileInfo, error) { return fakeFileInfo{dir: true}, nil })
+	if c.Status != StatusFail {
+		t.Fatalf("a directory path must FAIL, got %s", c.Status)
+	}
+}
+
+// Default injection (nil Executable/StatExecutable) resolves the real running
+// test binary — proving the production default path works and passes.
+func TestRuntimeCheckDefaultsToRealBinary(t *testing.T) {
+	c := runtimeCheck(Options{})
+	if c.Status != StatusPass {
+		t.Fatalf("default runtime check should pass for the running test binary, got %s (%q)", c.Status, c.Message)
+	}
+	if strings.TrimSpace(c.Details["binaryPath"].(string)) == "" {
+		t.Fatal("default runtime check should report the running binary path")
+	}
+}

internal/providercatalog/catalog.go

@@ -123,7 +123,6 @@ var descriptors = []Descriptor{
 	openAICompat("together", "Together AI", "https://api.together.xyz/v1", "meta-llama/Llama-3.3-70B-Instruct-Turbo", []string{"TOGETHER_API_KEY"}),
 	openAICompat("dashscope", "DashScope", "https://dashscope-intl.aliyuncs.com/compatible-mode/v1", "qwen-plus", []string{"DASHSCOPE_API_KEY", "QWEN_API_KEY"}, "qwen"),
 	openAICompat("moonshot", "Moonshot AI", "https://api.moonshot.ai/v1", "kimi-k2-0905-preview", []string{"MOONSHOT_API_KEY"}, "kimi"),
-	openAICompat("longcat", "LongCat", "https://api.longcat.chat/openai", "LongCat-2.0", []string{"LONGCAT_API_KEY"}, "meituan longcat", "meituan", "longcat-2.0"),
 	openAICompat("nvidia-nim", "NVIDIA NIM", "https://integrate.api.nvidia.com/v1", "nvidia/llama-3.1-nemotron-70b-instruct", []string{"NVIDIA_API_KEY"}, "nvidia nim"),
 	anthropicCompat("minimax", "MiniMax", "https://api.minimax.io/anthropic", "MiniMax-M3", []string{"MINIMAX_API_KEY"}, "mini-max", "mini_max"),
 	openAICompat("mistral", "Mistral", "https://api.mistral.ai/v1", "mistral-large-latest", []string{"MISTRAL_API_KEY"}),

internal/providercatalog/catalog_test.go

@@ -23,7 +23,6 @@ var expectedCatalogIDs = []string{
 	"together",
 	"dashscope",
 	"moonshot",
-	"longcat",
 	"nvidia-nim",
 	"minimax",
 	"mistral",
@@ -100,28 +99,6 @@ func TestRecommendedProviderEndpoint(t *testing.T) {
 	}
 }
 
-func TestLongCatDescriptor(t *testing.T) {
-	descriptor, err := Require("longcat")
-	if err != nil {
-		t.Fatalf("Require(longcat) error = %v", err)
-	}
-	if descriptor.Name != "LongCat" {
-		t.Fatalf("Name = %q, want LongCat", descriptor.Name)
-	}
-	if descriptor.DefaultBaseURL != "https://api.longcat.chat/openai" {
-		t.Fatalf("DefaultBaseURL = %q, want LongCat OpenAI-compatible endpoint", descriptor.DefaultBaseURL)
-	}
-	if descriptor.DefaultModel != "LongCat-2.0" {
-		t.Fatalf("DefaultModel = %q, want LongCat-2.0", descriptor.DefaultModel)
-	}
-	if descriptor.Transport != TransportOpenAICompatible {
-		t.Fatalf("Transport = %q, want %q", descriptor.Transport, TransportOpenAICompatible)
-	}
-	if !reflect.DeepEqual(descriptor.AuthEnvVars, []string{"LONGCAT_API_KEY"}) {
-		t.Fatalf("AuthEnvVars = %#v, want LONGCAT_API_KEY", descriptor.AuthEnvVars)
-	}
-}
-
 func TestCatalogDescriptorsExposeRequiredDefaults(t *testing.T) {
 	for _, descriptor := range All() {
 		if descriptor.ID == "" {
@@ -290,7 +267,7 @@ func TestListByTransportPreservesCatalogOrder(t *testing.T) {
 		TransportBedrock:         {"bedrock"},
 		TransportVertex:          {"vertex"},
 		TransportAnthropicCompat: {"minimax", "custom-anthropic-compatible"},
-		TransportOpenAICompat:    {"gitlawb-opengateway", "ollama-cloud", "ollama", "lmstudio", "openrouter", "huggingface", "chatgpt", "groq", "deepseek", "together", "dashscope", "moonshot", "longcat", "nvidia-nim", "mistral", "github", "xai", "venice", "xiaomi-mimo", "bankr", "zai", "kilocode", "opencode", "opencode-go", "atomic-chat", "chatgpt-proxy", "custom-openai-compatible"},
+		TransportOpenAICompat:    {"gitlawb-opengateway", "ollama-cloud", "ollama", "lmstudio", "openrouter", "huggingface", "chatgpt", "groq", "deepseek", "together", "dashscope", "moonshot", "nvidia-nim", "mistral", "github", "xai", "venice", "xiaomi-mimo", "bankr", "zai", "kilocode", "opencode", "opencode-go", "atomic-chat", "chatgpt-proxy", "custom-openai-compatible"},
 	}
 
 	for transport, wantIDs := range cases {