feat: show upload progress for batch file tasks (#228)

* feat: show upload progress for file tasks

* feat: show upload progress for batch file tasks

* style: distinguish download and upload phases

* style: mark successful task completion

* fix: preserve storage save error context

* fix: serialize single-file progress updates

* fix: stabilize batch upload progress reporting

Correct batch upload totals, completion state, actual file sizes, and synchronized progress snapshots. Add regression coverage for concurrent updates and phase transitions.

* feat: show per-file transfer progress

Format single-file and batch download and upload states with Telegram entities, blockquotes, speeds, transferred sizes, progress bars, concise counters, and accurate confirmation handling. Cover upload retries plus final, error, and cancellation messages with regression tests.

* chore: remove transfer progress tests

* test: restore critical transfer progress coverage

* test: cover interleaved batch transfers

* fix: declare progress styles in locale templates

core/tasks/batchtfile/task.go

@@ -31,16 +31,23 @@ type TaskElement struct {
 }
 
 type Task struct {
-	ID           string
-	ctx          context.Context
-	elems        []TaskElement
-	Progress     ProgressTracker
-	IgnoreErrors bool // if true, errors during processing will be ignored
-	downloaded   atomic.Int64
-	totalSize    int64
-	processing   map[string]TaskElementInfo
-	processingMu sync.RWMutex
-	failed       map[string]error // [TODO] errors for each element
+	ID              string
+	ctx             context.Context
+	elems           []TaskElement
+	Progress        ProgressTracker
+	IgnoreErrors    bool // if true, errors during processing will be ignored
+	downloaded      atomic.Int64
+	totalSize       int64
+	uploadTotalSize atomic.Int64
+	processing      map[string]TaskElementInfo
+	processingMu    sync.RWMutex
+	itemStates      []itemProgressState
+	itemIndex       map[string]int
+	itemMu          sync.RWMutex
+	uploadOnce      sync.Once
+	uploadMu        sync.Mutex
+	uploaded        map[string]int64
+	failed          map[string]error // [TODO] errors for each element
 }
 
 // Title implements core.Exectable.
@@ -109,6 +116,7 @@ func NewBatchTGFileTask(
 	progress ProgressTracker,
 	ignoreErrors bool,
 ) *Task {
+	itemStates, itemIndex := newItemProgressStates(files)
 	task := &Task{
 		ID:         id,
 		ctx:        ctx,
@@ -123,6 +131,9 @@ func NewBatchTGFileTask(
 			return total
 		}(),
 		processing:   make(map[string]TaskElementInfo),
+		itemStates:   itemStates,
+		itemIndex:    itemIndex,
+		uploaded:     make(map[string]int64),
 		IgnoreErrors: ignoreErrors,
 		processingMu: sync.RWMutex{},
 		failed:       make(map[string]error),