chore: rename simple_bank to api_tmpl and clean up for template use

Rename the module, proto service, and all identifiers from simple_bank/
SimpleBank to api_tmpl/ApiTmpl, and regenerate the gRPC/gateway/swagger/
mock code accordingly.

- Scrub real secrets (SMTP password, auth token secret) from api.env/
  api_test.env, untrack them, and add api.env.example/api_test.env.example
- Remove committed build artifacts (tmp/main, tmp/build-errors.log,
  dbml-error.log) and gitignore them going forward
- Fix Dockerfile paths (build target, migrations copy) that referenced a
  stale project layout
- Rewrite README to match the actual cmd/ + internal/ structure and add a
  "using this as a template" section

internal/auth/jwt_maker.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/FernandoJVideira/simple_bank/internal/config"
+	"github.com/FernandoJVideira/api_tmpl/internal/config"
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/google/uuid"
 )

internal/auth/jwt_maker_test.go

@@ -4,9 +4,9 @@ import (
 	"testing"
 	"time"
 
-	"github.com/FernandoJVideira/simple_bank/internal/config"
-	"github.com/FernandoJVideira/simple_bank/internal/domain/role"
-	"github.com/FernandoJVideira/simple_bank/pkg/testutil"
+	"github.com/FernandoJVideira/api_tmpl/internal/config"
+	"github.com/FernandoJVideira/api_tmpl/internal/domain/role"
+	"github.com/FernandoJVideira/api_tmpl/pkg/testutil"
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/stretchr/testify/require"
 )

internal/auth/paseto_maker.go

@@ -5,7 +5,7 @@ import (
 	"time"
 
 	"aidanwoods.dev/go-paseto"
-	"github.com/FernandoJVideira/simple_bank/internal/config"
+	"github.com/FernandoJVideira/api_tmpl/internal/config"
 	"github.com/google/uuid"
 )
 

internal/auth/paseto_maker_test.go

@@ -4,9 +4,9 @@ import (
 	"testing"
 	"time"
 
-	"github.com/FernandoJVideira/simple_bank/internal/config"
-	"github.com/FernandoJVideira/simple_bank/internal/domain/role"
-	"github.com/FernandoJVideira/simple_bank/pkg/testutil"
+	"github.com/FernandoJVideira/api_tmpl/internal/config"
+	"github.com/FernandoJVideira/api_tmpl/internal/domain/role"
+	"github.com/FernandoJVideira/api_tmpl/pkg/testutil"
 	"github.com/stretchr/testify/require"
 )