Refactor: Eliminate duplicate types - Use handler types directly

- Deleted templates.CollectionDetailData - using templates.CollectionData everywhere
- Deleted templates.BookData - using handlers.BookInfo everywhere
- Deleted templates.DeviceData - using handlers.DeviceInfo everywhere
- Deleted templates.ProgressItemData - using handlers.ProgressWithMedia everywhere
- Deleted templates.convertDevices() helper - Use handlers types directly in templates
- Enhanced handlers.ProgressWithMedia with device metadata fields
- Added handlers.getDeviceIcon() helper
- Updated all templates to import handlers package
- Cleaned up unused imports

This aligns codebase with templ's design philosophy (use Go types directly, no parallel type system)

internal/router/helpers.go

@@ -2,9 +2,7 @@ package router
 
 import (
 	"context"
-	"time"
 
-	"bookhoard/internal/handlers"
 	"bookhoard/templates"
 
 	"github.com/google/uuid"
@@ -43,29 +41,6 @@ func getTemplateUserWithTheme(c echo.Context, cfg *Config) (templates.User, erro
 	}, nil
 }
 
-func convertDevices(deviceInfos []handlers.DeviceInfo) []templates.DeviceData {
-	result := make([]templates.DeviceData, len(deviceInfos))
-	for i, d := range deviceInfos {
-		lastSync := ""
-		if d.LastSync != nil {
-			lastSync = d.LastSync.Format(time.RFC3339)
-		}
-		lastSeen := ""
-		if d.LastSeen != nil {
-			lastSeen = d.LastSeen.Format(time.RFC3339)
-		}
-		result[i] = templates.DeviceData{
-			ID:          d.ID.String(),
-			DeviceName:  d.DeviceName,
-			DeviceType:  d.DeviceType,
-			SyncEnabled: d.SyncEnabled,
-			LastSync:    lastSync,
-			LastSeen:    lastSeen,
-		}
-	}
-	return result
-}
-
 func convertPending(pending []map[string]interface{}) []templates.PendingRegistrationData {
 	result := make([]templates.PendingRegistrationData, len(pending))
 	for i, p := range pending {