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/routes_test.go

@@ -0,0 +1,160 @@
+package hws_test
+
+import (
+	"bytes"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"git.haelnorr.com/h/golib/hws"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_AddRoutes(t *testing.T) {
+	var buf bytes.Buffer
+
+	t.Run("No routes provided", func(t *testing.T) {
+		server := createTestServer(t, &buf)
+		err := server.AddRoutes()
+		assert.Error(t, err)
+		assert.Contains(t, err.Error(), "No routes provided")
+	})
+
+	t.Run("Single valid route", func(t *testing.T) {
+		server := createTestServer(t, &buf)
+		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		})
+		err := server.AddRoutes(hws.Route{
+			Path:    "/test",
+			Method:  hws.MethodGET,
+			Handler: handler,
+		})
+		assert.NoError(t, err)
+	})
+
+	t.Run("Multiple valid routes", func(t *testing.T) {
+		server := createTestServer(t, &buf)
+		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		})
+		err := server.AddRoutes(
+			hws.Route{Path: "/test1", Method: hws.MethodGET, Handler: handler},
+			hws.Route{Path: "/test2", Method: hws.MethodPOST, Handler: handler},
+			hws.Route{Path: "/test3", Method: hws.MethodPUT, Handler: handler},
+		)
+		assert.NoError(t, err)
+	})
+
+	t.Run("Invalid method", func(t *testing.T) {
+		server := createTestServer(t, &buf)
+		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		})
+		err := server.AddRoutes(hws.Route{
+			Path:    "/test",
+			Method:  hws.Method("INVALID"),
+			Handler: handler,
+		})
+		assert.Error(t, err)
+		assert.Contains(t, err.Error(), "Invalid method")
+	})
+
+	t.Run("No handler provided", func(t *testing.T) {
+		server := createTestServer(t, &buf)
+		err := server.AddRoutes(hws.Route{
+			Path:    "/test",
+			Method:  hws.MethodGET,
+			Handler: nil,
+		})
+		assert.Error(t, err)
+		assert.Contains(t, err.Error(), "No handler provided")
+	})
+
+	t.Run("All HTTP methods are valid", func(t *testing.T) {
+		methods := []hws.Method{
+			hws.MethodGET,
+			hws.MethodPOST,
+			hws.MethodPUT,
+			hws.MethodHEAD,
+			hws.MethodDELETE,
+			hws.MethodCONNECT,
+			hws.MethodOPTIONS,
+			hws.MethodTRACE,
+			hws.MethodPATCH,
+		}
+
+		for _, method := range methods {
+			t.Run(string(method), func(t *testing.T) {
+				server := createTestServer(t, &buf)
+				handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					w.WriteHeader(http.StatusOK)
+				})
+				err := server.AddRoutes(hws.Route{
+					Path:    "/test",
+					Method:  method,
+					Handler: handler,
+				})
+				assert.NoError(t, err)
+			})
+		}
+	})
+
+	t.Run("Healthz endpoint is automatically added", func(t *testing.T) {
+		server := createTestServer(t, &buf)
+		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		})
+		err := server.AddRoutes(hws.Route{
+			Path:    "/test",
+			Method:  hws.MethodGET,
+			Handler: handler,
+		})
+		require.NoError(t, err)
+
+		// Test using httptest instead of starting the server
+		req := httptest.NewRequest("GET", "/healthz", nil)
+		rr := httptest.NewRecorder()
+		server.Handler().ServeHTTP(rr, req)
+
+		assert.Equal(t, http.StatusOK, rr.Code)
+	})
+}
+
+func Test_Routes_EndToEnd(t *testing.T) {
+	var buf bytes.Buffer
+	server := createTestServer(t, &buf)
+
+	// Add multiple routes with different methods
+	getHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("GET response"))
+	})
+	postHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusCreated)
+		w.Write([]byte("POST response"))
+	})
+
+	err := server.AddRoutes(
+		hws.Route{Path: "/get", Method: hws.MethodGET, Handler: getHandler},
+		hws.Route{Path: "/post", Method: hws.MethodPOST, Handler: postHandler},
+	)
+	require.NoError(t, err)
+
+	// Test GET request using httptest
+	req := httptest.NewRequest("GET", "/get", nil)
+	rr := httptest.NewRecorder()
+	server.Handler().ServeHTTP(rr, req)
+	
+	assert.Equal(t, http.StatusOK, rr.Code)
+	assert.Equal(t, "GET response", rr.Body.String())
+
+	// Test POST request using httptest
+	req = httptest.NewRequest("POST", "/post", nil)
+	rr = httptest.NewRecorder()
+	server.Handler().ServeHTTP(rr, req)
+	
+	assert.Equal(t, http.StatusCreated, rr.Code)
+	assert.Equal(t, "POST response", rr.Body.String())
+}