feat: add HTTP-only cookie for browser authentication

- Set HTTP-only cookie in login handler for SSR authentication
- Set HTTP-only cookie in registration handler
- Change default redirect from /bookshelf to /dashboard
- Cookie enables browser page navigation without JavaScript

internal/handlers/auth.go

@@ -213,6 +213,17 @@ func (h *AuthHandler) Register(c echo.Context) error {
 		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to generate token"})
 	}
 
+	// Set HTTP-only cookie for browser-based authentication
+	cookie := &http.Cookie{
+		Name:     "token",
+		Value:    accessToken,
+		Path:     "/",
+		HttpOnly: true,
+		Secure:   false,
+		MaxAge:   3600,
+	}
+	c.SetCookie(cookie)
+
 	_, refreshToken, err := h.CreateRefreshToken(uuid.UUID(user.ID.Bytes))
 	if err != nil {
 		if c.Request().Header.Get("HX-Request") == "true" {
@@ -228,7 +239,7 @@ localStorage.setItem('token', '%s');
 localStorage.setItem('refreshToken', '%s');
 localStorage.setItem('user', JSON.stringify(%s));
 document.cookie = 'token=%s; path=/; max-age=3600';
-window.location.href = '/bookshelf';
+window.location.href = '/dashboard';
 </script>`, accessToken, refreshToken, fmt.Sprintf(`{"id":"%s","email":"%s","username":"%s"}`, uuid.UUID(user.ID.Bytes).String(), user.Email, user.Username), accessToken)
 		return c.HTML(http.StatusCreated, html)
 	}
@@ -348,6 +359,17 @@ func (h *AuthHandler) Login(c echo.Context) error {
 		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to generate token"})
 	}
 
+	// Set HTTP-only cookie for browser-based authentication
+	cookie := &http.Cookie{
+		Name:     "token",
+		Value:    accessToken,
+		Path:     "/",
+		HttpOnly: true,
+		Secure:   false,
+		MaxAge:   3600,
+	}
+	c.SetCookie(cookie)
+
 	_, refreshToken, err := h.CreateRefreshToken(uuid.UUID(user.ID.Bytes))
 	if err != nil {
 		if c.Request().Header.Get("HX-Request") == "true" {
@@ -359,7 +381,7 @@ func (h *AuthHandler) Login(c echo.Context) error {
 	if c.Request().Header.Get("HX-Request") == "true" {
 		redirect := c.FormValue("redirect")
 		if redirect == "" {
-			redirect = "/bookshelf"
+			redirect = "/dashboard"
 		}
 		html := fmt.Sprintf(`<div class="text-green-500">Login successful! Redirecting...</div>
 <script>