refactor: consolidate Require API and split lifecycle files

Add RequireOpts, RequireWithOpts, and GetModule. Move helpers to
lifecycle_internal.go and errors to errors.go. Remove unused GenericModule.

Co-authored-by: Cursor <cursoragent@cursor.com>

module.go

@@ -1,25 +1,14 @@
 package app
 
 import (
-	"errors"
 	"fmt"
 	"log/slog"
 	"strings"
 )
 
-// ErrModuleNotFound is returned when a module is not found in the lifecycle.
-var ErrModuleNotFound = errors.New("module not found")
-
 // ModuleFn is a function type for module setup and teardown functions.
 type ModuleFn func(*Module) error
 
-// GenericModule is an interface that allows modules to be extended with custom
-// functionality, as the module can return a pointer to the underlying Module.
-type GenericModule interface {
-	// Module returns the underlying Module instance.
-	Module() *Module
-}
-
 // Module represents a sub-system of the application, with its setup and
 // teardown functions and dependencies.
 type Module struct {
@@ -60,7 +49,8 @@ func (s *Module) Lifecycle() *Lifecycle {
 }
 
 // Logger returns the logger for the module. Uses the lifecycle's logger unless
-// a specific logger has been set during module load.
+// a specific logger has been set during module load. Panics if the module is
+// not associated with a lifecycle and no override logger was set.
 func (s *Module) Logger() *slog.Logger {
 	if s.logger != nil {
 		return s.logger