feat: implement Hybrid SSR for bookshelf page

- Add LibraryData type to templates/types.go
- Update bookshelf template to accept libraries parameter
- Render libraries server-side for faster initial page load
- Libraries now populated from server data instead of AJAX fetch
- JavaScript still uses API for dynamic content (bookshelf items)
- Update /bookshelf route to fetch libraries server-side before render
- Properly handle UUID and pgtype.Text conversions
- Maintain API endpoint compatibility for JavaScript calls

This improves initial page load performance while preserving
dynamic functionality via API calls.

cmd/server/main.go

@@ -339,20 +339,41 @@ func main() {
 
 	// Bookshelf route (protected) - new default for logged-in users
 	protected.GET("/bookshelf", func(c echo.Context) error {
-		userID := c.Get("user_id").(string)
-		userEmail := c.Get("user_email").(string)
-		userUsername := c.Get("user_username").(string)
-		userRole := c.Get("user_role").(string)
+		user := c.Get("user").(database.Users)
+		userUUID := uuid.UUID(user.ID.Bytes)
 
-		user := templates.User{
-			ID:       userID,
-			Email:    userEmail,
-			Username: userUsername,
-			Role:     userRole,
+		// Fetch libraries server-side for SSR
+		librariesData, err := libraryHandler.GetUserVisibleLibrariesData(c.Request().Context(), pgtype.UUID{Bytes: userUUID, Valid: true})
+		if err != nil {
+			return c.HTML(http.StatusInternalServerError, "Error loading libraries")
 		}
 
+		// Convert to template format
+		libraries := make([]templates.LibraryData, len(librariesData))
+		for i, lib := range librariesData {
+			libUUID := uuid.UUID(lib.ID.Bytes)
+			description := ""
+			if lib.Description.Valid {
+				description = lib.Description.String
+			}
+			libraries[i] = templates.LibraryData{
+				ID:          libUUID.String(),
+				Name:        lib.Name,
+				Description: description,
+				TypeName:    lib.TypeName,
+			}
+		}
+
+		userTemplate := templates.User{
+			ID:       userUUID.String(),
+			Email:    user.Email,
+			Username: user.Username,
+			Role:     user.Role,
+		}
+
+		// Render template WITH libraries data (SSR)
 		var buf bytes.Buffer
-		err := templates.BookShelf(user).Render(c.Request().Context(), &buf)
+		err = templates.BookShelf(userTemplate, libraries).Render(c.Request().Context(), &buf)
 		if err != nil {
 			return err
 		}