refactor(server): generate runtime configs and use .build/config for development

go/internal/server/authconfig/config.go

@@ -12,6 +12,8 @@ import (
 	"path/filepath"
 	"strings"
 	"time"
+
+	"bd2server/internal/server/configfile"
 )
 
 const FileName = "authentication.json"
@@ -52,11 +54,16 @@ type Public struct {
 	Providers []string `json:"providers"`
 }
 
+func Default() Config { return Config{Mode: "local"} }
+
 func Load(path string) (Config, error) {
 	path, err := filepath.Abs(filepath.Clean(path))
 	if err != nil {
 		return Config{}, fmt.Errorf("authconfig: resolve path: %w", err)
 	}
+	if err := configfile.Ensure(path, Default()); err != nil {
+		return Config{}, fmt.Errorf("authconfig: initialize %s: %w", path, err)
+	}
 	file, err := os.Open(path)
 	if err != nil {
 		return Config{}, fmt.Errorf("authconfig: open %s: %w", path, err)

go/internal/server/configfile/default.go

@@ -0,0 +1,51 @@
+// Package configfile publishes default configuration without replacing user files.
+package configfile
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log/slog"
+	"os"
+	"path/filepath"
+)
+
+// Ensure publishes a complete JSON file only when path does not exist.
+// Linking a same-directory temporary file makes publication atomic and refuses
+// to replace a configuration created by another process in the meantime.
+func Ensure(path string, defaults any) error {
+	if _, err := os.Stat(path); err == nil {
+		return nil
+	} else if !errors.Is(err, os.ErrNotExist) {
+		return err
+	}
+	data, err := json.MarshalIndent(defaults, "", "  ")
+	if err != nil {
+		return err
+	}
+	if err = os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+		return fmt.Errorf("create configuration directory: %w", err)
+	}
+	file, err := os.CreateTemp(filepath.Dir(path), ".config-*.tmp")
+	if err != nil {
+		return err
+	}
+	defer os.Remove(file.Name())
+	if _, err = file.Write(append(data, '\n')); err == nil {
+		err = file.Sync()
+	}
+	closeErr := file.Close()
+	if err != nil {
+		return err
+	}
+	if closeErr != nil {
+		return closeErr
+	}
+	if err = os.Link(file.Name(), path); errors.Is(err, os.ErrExist) {
+		return nil
+	} else if err != nil {
+		return fmt.Errorf("create default configuration %s: %w", path, err)
+	}
+	slog.Info("default configuration created", "path", path)
+	return nil
+}

go/internal/server/gameconfig/config.go

@@ -9,6 +9,8 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+
+	"bd2server/internal/server/configfile"
 )
 
 const FileName = "game.json"
@@ -48,13 +50,12 @@ func Default() Config {
 	return Config{SchemaVersion: 1, Story: StoryConfig{StartPackID: 21}, Purchases: PurchasesConfig{DiamondRecharge: DiamondRechargeConfig{Currency: "free", GoldPerPaidDiamond: 1000, DiamondsPerPaidDiamond: 1}}}
 }
 
-// Load reads one explicit path. Older installations without the file retain
-// the default rules; an existing invalid file must never silently fall back.
+// Load generates defaults when missing and strictly validates existing files.
 func Load(path string) (Config, error) {
-	data, err := os.ReadFile(filepath.Clean(path))
-	if errors.Is(err, os.ErrNotExist) {
-		return Default(), nil
+	if err := configfile.Ensure(path, Default()); err != nil {
+		return Config{}, fmt.Errorf("game configuration: initialize %s: %w", path, err)
 	}
+	data, err := os.ReadFile(filepath.Clean(path))
 	if err != nil {
 		return Config{}, fmt.Errorf("game configuration: read %s: %w", path, err)
 	}

go/internal/server/gameconfig/config_test.go

@@ -74,14 +74,14 @@ func TestStartingChapterConfiguration(t *testing.T) {
 	}
 }
 
-func TestMissingFileDefaultsWithoutCreating(t *testing.T) {
+func TestMissingFileCreatesDefaults(t *testing.T) {
 	path := filepath.Join(t.TempDir(), FileName)
 	cfg, err := Load(path)
 	if err != nil || cfg != Default() {
 		t.Fatalf("config = %+v, error = %v", cfg, err)
 	}
-	if _, err := os.Stat(path); !os.IsNotExist(err) {
-		t.Fatalf("Load created missing config: %v", err)
+	if _, err := os.Stat(path); err != nil {
+		t.Fatalf("Load did not create missing config: %v", err)
 	}
 }
 

go/internal/server/gamedata/waypoint_cache_benchmark_test.go

@@ -1,69 +0,0 @@
-package gamedata
-
-import (
-	"os"
-	"testing"
-)
-
-// Opt-in performance verification, not a source for game design assertions.
-func BenchmarkInstalledWaypointPackWarm(b *testing.B) {
-	root := os.Getenv("BD2_REAL_GAMEDATA")
-	if root == "" {
-		b.Skip("BD2_REAL_GAMEDATA not configured")
-	}
-	if err := CloseDatabaseCache(); err != nil {
-		b.Fatal(err)
-	}
-	b.Cleanup(func() {
-		if err := CloseDatabaseCache(); err != nil {
-			b.Error(err)
-		}
-	})
-	if _, err := LoadWaypointPack(root, "20260923193640", 21); err != nil {
-		b.Fatal(err)
-	}
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		if _, err := LoadWaypointPack(root, "20260923193640", 21); err != nil {
-			b.Fatal(err)
-		}
-	}
-}
-
-func BenchmarkInstalledWaypointPackCold(b *testing.B) {
-	root := os.Getenv("BD2_REAL_GAMEDATA")
-	if root == "" {
-		b.Skip("BD2_REAL_GAMEDATA not configured")
-	}
-	b.Cleanup(func() { _ = CloseDatabaseCache() })
-	for i := 0; i < b.N; i++ {
-		b.StopTimer()
-		if err := CloseDatabaseCache(); err != nil {
-			b.Fatal(err)
-		}
-		b.StartTimer()
-		if _, err := LoadWaypointPack(root, "20260923193640", 21); err != nil {
-			b.Fatal(err)
-		}
-	}
-}
-
-func BenchmarkInstalledPackDetailWarm(b *testing.B) {
-	root := os.Getenv("BD2_REAL_GAMEDATA")
-	if root == "" {
-		b.Skip("BD2_REAL_GAMEDATA not configured")
-	}
-	if err := CloseDatabaseCache(); err != nil {
-		b.Fatal(err)
-	}
-	b.Cleanup(func() { _ = CloseDatabaseCache() })
-	if _, err := LoadPackDetailDesign(root, "20260923193640", 21); err != nil {
-		b.Fatal(err)
-	}
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		if _, err := LoadPackDetailDesign(root, "20260923193640", 21); err != nil {
-			b.Fatal(err)
-		}
-	}
-}

go/internal/server/resourcepolicy/config.go

@@ -11,6 +11,8 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+
+	"bd2server/internal/server/configfile"
 )
 
 const (
@@ -51,6 +53,9 @@ func Default() Config {
 // Load reads one explicit resources.json. Unknown fields and trailing JSON are
 // rejected so a misspelled URL key cannot silently fall back to another CDN.
 func Load(path string) (Config, error) {
+	if err := configfile.Ensure(path, Default()); err != nil {
+		return Config{}, fmt.Errorf("resource policy: initialize %s: %w", path, err)
+	}
 	data, err := os.ReadFile(filepath.Clean(path))
 	if err != nil {
 		return Config{}, fmt.Errorf("resource policy: read %s: %w", path, err)