feat(firebase)!: promote to v1.0.0 — cache auth.Client, adopt xerrors, bump deps to v1

Cache auth.Client in OnInit (eliminates per-probe app.Auth call in HealthCheck).
Replace all fmt.Errorf with xerrors structured errors (ErrInvalidInput / ErrInternal).
Bump health/launcher/logz to v1.0.1, add xerrors v1.0.1, Go directive to 1.26.
API committed as stable.

firebase.go

@@ -2,7 +2,6 @@ package firebase
 
 import (
 	"context"
-	"fmt"
 
 	fb "firebase.google.com/go/v4"
 	"firebase.google.com/go/v4/auth"
@@ -10,6 +9,7 @@ import (
 	"code.nochebuena.dev/go/health"
 	"code.nochebuena.dev/go/launcher"
 	"code.nochebuena.dev/go/logz"
+	"code.nochebuena.dev/go/xerrors"
 )
 
 // Provider is the minimal interface for consumers that only need the firebase App.
@@ -31,9 +31,10 @@ type Config struct {
 }
 
 type firebaseComponent struct {
-	cfg    Config
-	logger logz.Logger
-	app    *fb.App
+	cfg        Config
+	logger     logz.Logger
+	app        *fb.App
+	authClient *auth.Client
 }
 
 // New returns a firebase Component. Call lc.Append(fb) to manage its lifecycle.
@@ -43,7 +44,7 @@ func New(logger logz.Logger, cfg Config) Component {
 
 func (f *firebaseComponent) OnInit() error {
 	if f.cfg.ProjectID == "" {
-		return fmt.Errorf("firebase: ProjectID is required")
+		return xerrors.New(xerrors.ErrInvalidInput, "firebase: ProjectID is required")
 	}
 	f.logger.Info("firebase: initializing app", "project_id", f.cfg.ProjectID)
 	app, err := fb.NewApp(context.Background(), &fb.Config{
@@ -51,9 +52,14 @@ func (f *firebaseComponent) OnInit() error {
 	})
 	if err != nil {
 		f.logger.Error("firebase: failed to create app", err)
-		return fmt.Errorf("firebase: create app: %w", err)
+		return xerrors.Wrap(xerrors.ErrInternal, "firebase: create app", err)
 	}
 	f.app = app
+	authClient, err := app.Auth(context.Background())
+	if err != nil {
+		return xerrors.Wrap(xerrors.ErrInternal, "firebase: get auth client", err)
+	}
+	f.authClient = authClient
 	return nil
 }
 
@@ -70,14 +76,10 @@ func (f *firebaseComponent) OnStop() error {
 func (f *firebaseComponent) App() *fb.App { return f.app }
 
 func (f *firebaseComponent) HealthCheck(ctx context.Context) error {
-	if f.app == nil {
-		return fmt.Errorf("firebase: app not initialized")
+	if f.authClient == nil {
+		return xerrors.New(xerrors.ErrInternal, "firebase: app not initialized")
 	}
-	authClient, err := f.app.Auth(ctx)
-	if err != nil {
-		return fmt.Errorf("firebase: get auth client: %w", err)
-	}
-	_, err = authClient.GetUser(ctx, "health-probe-non-existent")
+	_, err := f.authClient.GetUser(ctx, "health-probe-non-existent")
 	if err != nil {
 		if auth.IsUserNotFound(err) {
 			return nil // expected: probe of non-existent UID succeeded