Refactor database interface to use *sql.DB directly

Simplified the database layer by removing custom interface wrappers
and using standard library *sql.DB and *sql.Tx types directly.

Changes:
- Removed DBConnection and DBTransaction interfaces from database.go
- Removed NewDBConnection() wrapper function
- Updated TokenGenerator to use *sql.DB instead of DBConnection
- Updated all validation and revocation methods to accept *sql.Tx
- Updated TableManager to work with *sql.DB directly
- Updated all tests to use db.Begin() instead of custom wrappers
- Fixed GeneratorConfig.DB field (was DBConn)
- Updated documentation in doc.go with correct API usage

Benefits:
- Simpler API with fewer abstractions
- Works directly with database/sql standard library
- Compatible with GORM (via gormDB.DB()) and Bun (share same *sql.DB)
- Easier to understand and maintain
- No unnecessary wrapper layers

Breaking changes:
- GeneratorConfig.DBConn renamed to GeneratorConfig.DB
- Removed NewDBConnection() function - pass *sql.DB directly
- ValidateAccess/ValidateRefresh now accept *sql.Tx instead of DBTransaction
- Token.Revoke/CheckNotRevoked now accept *sql.Tx instead of DBTransaction

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

hws/config_test.go

@@ -0,0 +1,120 @@
+package hws_test
+
+import (
+	"os"
+	"testing"
+	"time"
+
+	"git.haelnorr.com/h/golib/hws"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_ConfigFromEnv(t *testing.T) {
+	t.Run("Default values when no env vars set", func(t *testing.T) {
+		// Clear any existing env vars
+		os.Unsetenv("HWS_HOST")
+		os.Unsetenv("HWS_PORT")
+		os.Unsetenv("HWS_TRUSTED_HOST")
+		os.Unsetenv("HWS_GZIP")
+		os.Unsetenv("HWS_READ_HEADER_TIMEOUT")
+		os.Unsetenv("HWS_WRITE_TIMEOUT")
+		os.Unsetenv("HWS_IDLE_TIMEOUT")
+
+		config, err := hws.ConfigFromEnv()
+		require.NoError(t, err)
+		require.NotNil(t, config)
+
+		assert.Equal(t, "127.0.0.1", config.Host)
+		assert.Equal(t, uint64(3000), config.Port)
+		assert.Equal(t, "127.0.0.1", config.TrustedHost)
+		assert.Equal(t, false, config.GZIP)
+		assert.Equal(t, 2*time.Second, config.ReadHeaderTimeout)
+		assert.Equal(t, 10*time.Second, config.WriteTimeout)
+		assert.Equal(t, 120*time.Second, config.IdleTimeout)
+	})
+
+	t.Run("Custom host", func(t *testing.T) {
+		os.Setenv("HWS_HOST", "192.168.1.1")
+		defer os.Unsetenv("HWS_HOST")
+
+		config, err := hws.ConfigFromEnv()
+		require.NoError(t, err)
+		assert.Equal(t, "192.168.1.1", config.Host)
+		assert.Equal(t, "192.168.1.1", config.TrustedHost) // Should match host by default
+	})
+
+	t.Run("Custom port", func(t *testing.T) {
+		os.Setenv("HWS_PORT", "8080")
+		defer os.Unsetenv("HWS_PORT")
+
+		config, err := hws.ConfigFromEnv()
+		require.NoError(t, err)
+		assert.Equal(t, uint64(8080), config.Port)
+	})
+
+	t.Run("Custom trusted host", func(t *testing.T) {
+		os.Setenv("HWS_HOST", "127.0.0.1")
+		os.Setenv("HWS_TRUSTED_HOST", "example.com")
+		defer os.Unsetenv("HWS_HOST")
+		defer os.Unsetenv("HWS_TRUSTED_HOST")
+
+		config, err := hws.ConfigFromEnv()
+		require.NoError(t, err)
+		assert.Equal(t, "127.0.0.1", config.Host)
+		assert.Equal(t, "example.com", config.TrustedHost)
+	})
+
+	t.Run("GZIP enabled", func(t *testing.T) {
+		os.Setenv("HWS_GZIP", "true")
+		defer os.Unsetenv("HWS_GZIP")
+
+		config, err := hws.ConfigFromEnv()
+		require.NoError(t, err)
+		assert.Equal(t, true, config.GZIP)
+	})
+
+	t.Run("Custom timeouts", func(t *testing.T) {
+		os.Setenv("HWS_READ_HEADER_TIMEOUT", "5")
+		os.Setenv("HWS_WRITE_TIMEOUT", "30")
+		os.Setenv("HWS_IDLE_TIMEOUT", "300")
+		defer os.Unsetenv("HWS_READ_HEADER_TIMEOUT")
+		defer os.Unsetenv("HWS_WRITE_TIMEOUT")
+		defer os.Unsetenv("HWS_IDLE_TIMEOUT")
+
+		config, err := hws.ConfigFromEnv()
+		require.NoError(t, err)
+		assert.Equal(t, 5*time.Second, config.ReadHeaderTimeout)
+		assert.Equal(t, 30*time.Second, config.WriteTimeout)
+		assert.Equal(t, 300*time.Second, config.IdleTimeout)
+	})
+
+	t.Run("All custom values", func(t *testing.T) {
+		os.Setenv("HWS_HOST", "0.0.0.0")
+		os.Setenv("HWS_PORT", "9000")
+		os.Setenv("HWS_TRUSTED_HOST", "myapp.com")
+		os.Setenv("HWS_GZIP", "true")
+		os.Setenv("HWS_READ_HEADER_TIMEOUT", "3")
+		os.Setenv("HWS_WRITE_TIMEOUT", "15")
+		os.Setenv("HWS_IDLE_TIMEOUT", "180")
+		defer func() {
+			os.Unsetenv("HWS_HOST")
+			os.Unsetenv("HWS_PORT")
+			os.Unsetenv("HWS_TRUSTED_HOST")
+			os.Unsetenv("HWS_GZIP")
+			os.Unsetenv("HWS_READ_HEADER_TIMEOUT")
+			os.Unsetenv("HWS_WRITE_TIMEOUT")
+			os.Unsetenv("HWS_IDLE_TIMEOUT")
+		}()
+
+		config, err := hws.ConfigFromEnv()
+		require.NoError(t, err)
+		assert.Equal(t, "0.0.0.0", config.Host)
+		assert.Equal(t, uint64(9000), config.Port)
+		assert.Equal(t, "myapp.com", config.TrustedHost)
+		assert.Equal(t, true, config.GZIP)
+		assert.Equal(t, 3*time.Second, config.ReadHeaderTimeout)
+		assert.Equal(t, 15*time.Second, config.WriteTimeout)
+		assert.Equal(t, 180*time.Second, config.IdleTimeout)
+	})
+}