merge trails function added (#627)

* merge trails function added

* fix conflict resolve issues

* avoid incorrect authorship when merging trail comments

* require edit access for all selected trails before merge

* fix likes checkbox binding in trail merge modal

* improve error handling

* require editable target and deletable sources for merge

* avoid duplicate trail fetch during merge

* prevent duplicate likes when merging trails

* check photo download responses during trail merge

* add merge completion toast notifications

* cleanup

* small fixes

* move merge code to backend, option to merge single trail selection with similar one, automatic merge for integrations add as option, maintenance page to find and merge similar trails added

* fix build error

* fix

* docu, beautifying, refactoring

---------

Co-authored-by: Flomp <Flomp@users.noreply.github.com>

db/integrations/komoot/models.go

@@ -1,14 +1,19 @@
 package komoot
 
-import "time"
+import (
+	"time"
+
+	"pocketbase/trailmerge"
+)
 
 type KomootIntegration struct {
-	Active    bool   `json:"active"`
-	Email     string `json:"email"`
-	Password  string `json:"password"`
-	Planned   bool   `json:"planned"`
-	Completed bool   `json:"completed"`
-	Privacy   string `json:"privacy"`
+	Active    bool                                    `json:"active"`
+	Email     string                                  `json:"email"`
+	Password  string                                  `json:"password"`
+	Planned   bool                                    `json:"planned"`
+	Completed bool                                    `json:"completed"`
+	Privacy   string                                  `json:"privacy"`
+	Merge     trailmerge.IntegrationAutoMergeSettings `json:"merge"`
 }
 
 type LoginResponse struct {