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.go

@@ -0,0 +1,35 @@
+package hws
+
+import (
+	"time"
+
+	"git.haelnorr.com/h/golib/env"
+)
+
+type Config struct {
+	Host              string        // ENV HWS_HOST: Host to listen on (default: 127.0.0.1)
+	Port              uint64        // ENV HWS_PORT: Port to listen on (default: 3000)
+	TrustedHost       string        // ENV HWS_TRUSTED_HOST: Domain/Hostname to accept as trusted (default: same as Host)
+	GZIP              bool          // ENV HWS_GZIP: Flag for GZIP compression on requests (default: false)
+	ReadHeaderTimeout time.Duration // ENV HWS_READ_HEADER_TIMEOUT: Timeout for reading request headers in seconds (default: 2)
+	WriteTimeout      time.Duration // ENV HWS_WRITE_TIMEOUT: Timeout for writing requests in seconds (default: 10)
+	IdleTimeout       time.Duration // ENV HWS_IDLE_TIMEOUT: Timeout for idle connections in seconds (default: 120)
+}
+
+// ConfigFromEnv returns a Config struct loaded from the environment variables
+func ConfigFromEnv() (*Config, error) {
+	host := env.String("HWS_HOST", "127.0.0.1")
+	trustedHost := env.String("HWS_TRUSTED_HOST", host)
+
+	cfg := &Config{
+		Host:              host,
+		Port:              env.UInt64("HWS_PORT", 3000),
+		TrustedHost:       trustedHost,
+		GZIP:              env.Bool("HWS_GZIP", false),
+		ReadHeaderTimeout: time.Duration(env.Int("HWS_READ_HEADER_TIMEOUT", 2)) * time.Second,
+		WriteTimeout:      time.Duration(env.Int("HWS_WRITE_TIMEOUT", 10)) * time.Second,
+		IdleTimeout:       time.Duration(env.Int("HWS_IDLE_TIMEOUT", 120)) * time.Second,
+	}
+
+	return cfg, nil
+}