feat(routing): cmd/routing binary

Wires Config → LiteLLMExecutor → Router → four skills (review, debug,
retrospective, trainer) → Registry → MCP server with bearer auth and
/healthz. Each skill's CompleteFunc is wrapped so the Router decides
local-vs-Claude per call and logs every decision to the brain /mcp.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cmd/routing/main_test.go

@@ -0,0 +1,123 @@
+package main_test
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os/exec"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestRoutingPodEndToEnd boots the binary against fake LiteLLM + brain servers,
+// calls tools/list and one tools/call, and verifies the brain saw a session_log POST.
+func TestRoutingPodEndToEnd(t *testing.T) {
+	if testing.Short() {
+		t.Skip("end-to-end binary boot")
+	}
+
+	var brainHits int
+	llm := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"choices": []map[string]any{{"message": map[string]any{"role": "assistant", "content": "stub"}}},
+		})
+	}))
+	defer llm.Close()
+
+	brain := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/pass-rate":
+			brainHits++
+			_ = json.NewEncoder(w).Encode(map[string]any{"pass_rate": 0.95})
+		case "/mcp":
+			brainHits++
+			_ = json.NewEncoder(w).Encode(map[string]any{"jsonrpc": "2.0", "id": 1, "result": map[string]any{}})
+		}
+	}))
+	defer brain.Close()
+
+	bin := buildRouting(t)
+	cmd := exec.Command(bin)
+	cmd.Env = append(cmd.Env,
+		"ROUTING_PORT=33310",
+		"LITELLM_BASE_URL="+llm.URL,
+		"LITELLM_API_KEY=stub",
+		"BRAIN_URL="+brain.URL,
+		"SUPERVISOR_CONFIG_DIR=../../config/supervisor",
+		"PATH="+osPath(),
+	)
+	require.NoError(t, cmd.Start())
+	t.Cleanup(func() { _ = cmd.Process.Kill() })
+
+	require.NoError(t, waitForPort(t, "127.0.0.1:33310", 5*time.Second))
+
+	resp := mcpCall(t, "http://127.0.0.1:33310/mcp", `{"jsonrpc":"2.0","id":1,"method":"tools/list"}`)
+	assert.Contains(t, resp, `"review"`)
+	assert.Contains(t, resp, `"debug"`)
+	assert.Contains(t, resp, `"retrospective"`)
+	assert.Contains(t, resp, `"trainer"`)
+
+	resp = mcpCall(t, "http://127.0.0.1:33310/mcp", `{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"review","arguments":{"project_root":"/tmp","files":["README.md"]}}}`)
+	_ = resp // shape varies by skill; we only need a 200
+
+	// Wait briefly for the async session_log to land.
+	deadline := time.Now().Add(2 * time.Second)
+	for time.Now().Before(deadline) && brainHits < 2 {
+		time.Sleep(50 * time.Millisecond)
+	}
+	assert.GreaterOrEqual(t, brainHits, 2, "expected at least one /pass-rate hit and one /mcp session_log hit")
+}
+
+func buildRouting(t *testing.T) string {
+	t.Helper()
+	bin := t.TempDir() + "/routing"
+	out, err := exec.Command("go", "build", "-o", bin, "github.com/mathiasbq/supervisor/cmd/routing").CombinedOutput()
+	require.NoError(t, err, "build failed: %s", out)
+	return bin
+}
+
+func waitForPort(_ *testing.T, addr string, dur time.Duration) error {
+	deadline := time.Now().Add(dur)
+	for time.Now().Before(deadline) {
+		c, err := http.Get("http://" + addr + "/healthz") //nolint:noctx
+		if err == nil {
+			_ = c.Body.Close()
+			return nil
+		}
+		conn, err := http.NewRequest(http.MethodPost, "http://"+addr+"/mcp", strings.NewReader(`{}`))
+		if err == nil {
+			r, err := http.DefaultClient.Do(conn)
+			if err == nil {
+				_ = r.Body.Close()
+				return nil
+			}
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+	return context.DeadlineExceeded
+}
+
+func mcpCall(t *testing.T, url, body string) string {
+	t.Helper()
+	r, err := http.Post(url, "application/json", strings.NewReader(body)) //nolint:noctx
+	require.NoError(t, err)
+	defer func() { _ = r.Body.Close() }()
+	raw, err := io.ReadAll(r.Body)
+	require.NoError(t, err)
+	return string(raw)
+}
+
+func osPath() string {
+	for _, e := range append([]string{}, exec.Command("env").Env...) {
+		if strings.HasPrefix(e, "PATH=") {
+			return strings.TrimPrefix(e, "PATH=")
+		}
+	}
+	return "/usr/bin:/bin"
+}