Add habit HTTP endpoints

- Create DTOs for HTTP requests and responses
- Implement habit handlers (create, get today's, mark)
- Register routes in router: POST /habits, GET /habits/today, POST /habits/{id}/mark
- Add missing repository methods (FindByID, FindByHabitID, FindPendingByHabitID, Delete)
- Wire up dependencies in main.go
- Tested with curl: create, list, mark habits work correctly

internal/infrastructure/http/router.go

@@ -8,7 +8,7 @@ import (
 	"github.com/go-chi/cors"
 )
 
-func NewRouter(corsOrigins string) *chi.Mux {
+func NewRouter(corsOrigins string, habitHandlers *HabitHandlers) *chi.Mux {
 	r := chi.NewRouter()
 
 	r.Use(middleware.Logger)
@@ -25,5 +25,11 @@ func NewRouter(corsOrigins string) *chi.Mux {
 		w.Write([]byte(`{"status":"ok"}`))
 	})
 
+	r.Route("/api/v1/habits", func(r chi.Router) {
+		r.Post("/", habitHandlers.CreateHabit)
+		r.Get("/today", habitHandlers.GetTodaysHabits)
+		r.Post("/{id}/mark", habitHandlers.MarkHabit)
+	})
+
 	return r
 }