feat: wire all components in main.go

Replaces the stub with the actual supervisor entrypoint: loads config,
reads supervisor CLAUDE.md and tdd.md, constructs the executor and TDD
skill, registers them, and starts the HTTP/MCP server.

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

cmd/supervisor/main.go

@@ -1,11 +1,66 @@
 package main
 
 import (
-	"fmt"
+	"log/slog"
+	"net/http"
 	"os"
+
+	"github.com/mathiasbq/supervisor/internal/config"
+	iexec "github.com/mathiasbq/supervisor/internal/exec"
+	"github.com/mathiasbq/supervisor/internal/mcp"
+	"github.com/mathiasbq/supervisor/internal/registry"
+	"github.com/mathiasbq/supervisor/internal/skills/tdd"
 )
 
 func main() {
-	fmt.Fprintln(os.Stderr, "supervisor: not yet implemented")
-	os.Exit(1)
+	logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
+
+	cfg, err := config.Load()
+	if err != nil {
+		logger.Error("load config", "err", err)
+		os.Exit(1)
+	}
+
+	models, err := config.LoadModels(cfg.ModelsFile)
+	if err != nil {
+		logger.Error("load models", "err", err)
+		os.Exit(1)
+	}
+
+	systemPrompt, err := os.ReadFile(cfg.ConfigDir + "/CLAUDE.md")
+	if err != nil {
+		logger.Error("read supervisor CLAUDE.md", "path", cfg.ConfigDir+"/CLAUDE.md", "err", err)
+		os.Exit(1)
+	}
+
+	tddPrompt, err := os.ReadFile(cfg.ConfigDir + "/tdd.md")
+	if err != nil {
+		logger.Error("read tdd.md", "path", cfg.ConfigDir+"/tdd.md", "err", err)
+		os.Exit(1)
+	}
+
+	executor := iexec.New(iexec.Config{
+		SystemPrompt:   string(systemPrompt),
+		LiteLLMBaseURL: cfg.LiteLLMBaseURL,
+		LiteLLMAPIKey:  cfg.LiteLLMAPIKey,
+	})
+
+	reg := registry.New()
+	reg.Register(tdd.New(tdd.Config{
+		SystemPrompt: string(systemPrompt),
+		SkillPrompt:  string(tddPrompt),
+		DefaultModel: models.Resolve("tdd", ""),
+		ExecutorFn:   executor.Run,
+	}))
+
+	srv := mcp.NewServer(reg)
+	mux := http.NewServeMux()
+	mux.Handle("/mcp", srv)
+
+	addr := ":" + cfg.Port
+	logger.Info("supervisor starting", "addr", addr)
+	if err := http.ListenAndServe(addr, mux); err != nil {
+		logger.Error("server stopped", "err", err)
+		os.Exit(1)
+	}
 }