fix: correct default data directory to ~/.kandev/data (#389)

apps/backend/internal/common/config/config.go

@@ -31,7 +31,7 @@ type Config struct {
 
 // ResolvedDataDir returns the base data directory for Kandev.
 // Config.DataDir is populated by Viper from the config file or KANDEV_DATA_DIR env var.
-// If empty, falls back to ~/.kandev.
+// If empty, falls back to ~/.kandev/data.
 func (c *Config) ResolvedDataDir() string {
 	if c.DataDir != "" {
 		if strings.HasPrefix(c.DataDir, "~/") {
@@ -43,9 +43,9 @@ func (c *Config) ResolvedDataDir() string {
 	}
 	home, err := os.UserHomeDir()
 	if err != nil {
-		return ".kandev"
+		return filepath.Join(".kandev", "data")
 	}
-	return filepath.Join(home, ".kandev")
+	return filepath.Join(home, ".kandev", "data")
 }
 
 // ServerConfig holds HTTP server configuration.
@@ -198,7 +198,7 @@ func setDefaults(v *viper.Viper) {
 	v.SetDefault("server.readTimeout", 30)
 	v.SetDefault("server.writeTimeout", 30)
 
-	// DataDir default — empty means resolve from KANDEV_DATA_DIR env or ~/.kandev
+	// DataDir default — empty means resolve from KANDEV_DATA_DIR env or ~/.kandev/data
 	v.SetDefault("dataDir", "")
 
 	// Database defaults

apps/backend/internal/common/config/config_test.go

@@ -19,7 +19,7 @@ func TestResolvedDataDir_FallbackToHome(t *testing.T) {
 	if err != nil {
 		t.Skip("cannot determine home directory")
 	}
-	want := filepath.Join(home, ".kandev")
+	want := filepath.Join(home, ".kandev", "data")
 	if got := cfg.ResolvedDataDir(); got != want {
 		t.Errorf("ResolvedDataDir() = %q, want %q", got, want)
 	}

apps/backend/internal/common/portutil/portutil_test.go

@@ -1,6 +1,7 @@
 package portutil
 
 import (
+	"net"
 	"strings"
 	"testing"
 )
@@ -19,15 +20,23 @@ func TestAllocatePort(t *testing.T) {
 }
 
 func TestAllocatePortUniqueness(t *testing.T) {
-	// Allocate multiple ports and ensure they're different
+	// Hold all listeners open to prevent the OS from reassigning freed ports.
 	ports := make(map[int]bool)
-	for i := 0; i < 10; i++ {
-		port, err := AllocatePort()
-		if err != nil {
-			t.Fatalf("AllocatePort() failed on iteration %d: %v", i, err)
+	listeners := make([]net.Listener, 0, 10)
+	defer func() {
+		for _, l := range listeners {
+			_ = l.Close()
 		}
+	}()
+	for i := 0; i < 10; i++ {
+		l, err := net.Listen("tcp", ":0")
+		if err != nil {
+			t.Fatalf("Listen failed on iteration %d: %v", i, err)
+		}
+		listeners = append(listeners, l)
+		port := l.Addr().(*net.TCPAddr).Port
 		if ports[port] {
-			t.Errorf("AllocatePort() returned duplicate port: %d", port)
+			t.Errorf("duplicate port: %d", port)
 		}
 		ports[port] = true
 	}

docs/db.md

@@ -10,14 +10,14 @@ SQLite requires no external services and works out of the box.
 
 | Variable | Default | Description |
 |----------|---------|-------------|
-| `KANDEV_DATA_DIR` | `~/.kandev` | Base directory for all data (DB, worktrees, sessions, etc.) |
+| `KANDEV_DATA_DIR` | `~/.kandev/data` | Base directory for all data (DB, worktrees, sessions, etc.) |
 | `KANDEV_DATABASE_DRIVER` | `sqlite` | Database driver |
 | `KANDEV_DATABASE_PATH` | `$KANDEV_DATA_DIR/kandev.db` | Path to the SQLite database file (override) |
 
 ### Config file (`config.yaml`)
 
 ```yaml
-dataDir: ""  # empty = resolve from KANDEV_DATA_DIR or ~/.kandev
+dataDir: ""  # empty = resolve from KANDEV_DATA_DIR or ~/.kandev/data
 database:
   driver: sqlite
   path: ""   # empty = $dataDir/kandev.db