Admin UI: Fetch task logs (#7114)

* show task details

* loading tasks

* task UI works

* generic rendering

* rendering the export link

* removing placementConflicts from task parameters

* remove TaskSourceLocation

* remove "Server ID" column

* rendering balance task source

* sources and targets

* fix ec task generation

* move info

* render timeline

* simplified worker id

* simplify

* read task logs from worker

* isValidTaskID

* address comments

* Update weed/worker/tasks/balance/execution.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update weed/worker/tasks/erasure_coding/ec_task.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update weed/worker/tasks/task_log_handler.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix shard ids

* plan distributing shard id

* rendering planned shards in task details

* remove Conflicts

* worker logs correctly

* pass in dc and rack

* task logging

* Update weed/admin/maintenance/maintenance_queue.go

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* display log details

* logs have fields now

* sort field keys

* fix link

* fix collection filtering

* avoid hard coded ec shard counts

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

weed/worker/tasks/task_logger.go

@@ -127,7 +127,7 @@ func NewTaskLogger(taskID string, taskType types.TaskType, workerID string, para
 		Status:      "started",
 		Progress:    0.0,
 		VolumeID:    params.VolumeID,
-		Server:      params.Server,
+		Server:      getServerFromSources(params.TypedParams.Sources),
 		Collection:  params.Collection,
 		CustomData:  make(map[string]interface{}),
 		LogFilePath: logFilePath,
@@ -149,7 +149,7 @@ func NewTaskLogger(taskID string, taskType types.TaskType, workerID string, para
 	logger.Info("Task logger initialized for %s (type: %s, worker: %s)", taskID, taskType, workerID)
 	logger.LogWithFields("INFO", "Task parameters", map[string]interface{}{
 		"volume_id":  params.VolumeID,
-		"server":     params.Server,
+		"server":     getServerFromSources(params.TypedParams.Sources),
 		"collection": params.Collection,
 	})