v0.147.2 — 4c follow-up 2: when NO counter can move, say what is being worked on

The v0.147.1 file-count fallback fixed the incremental case but not the one the
demo box actually hits. Watching a second real run: bookstack reported clean byte
progress (100%, 154.0 MB, 7/7 files — the byte path works), while immich sat at
files_done 1 of 46, bytes_done 0, for 42 seconds.

restic 0.14 only counts a file into bytes_done/files_done when it COMPLETES, so
an app dominated by a single large archive (immich's ~430MB volume tar) freezes
both counters. No percentage can move in that window, so stop trying to fake one.

restic keeps reporting current_files and seconds_elapsed throughout. The card now
names the file being processed and the elapsed time: "1 / 46 fájl (430.2 MB) ·
feldolgozás alatt: immich_upload.tar · 42 mp". "Working on this file for 42
seconds" is a completely different message from "0%", and it is the honest one.

The last known current_files value persists across ticks that omit it (restic
does not send it every tick, and blanking the label every other second is its own
flicker); switching app clears it so one app's file is never shown against
another. Both pinned by tests, with the real 42-second status line shape.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Nn3VgQk9iwEGgyx6QJ2NvE

controller/internal/backup/offbox_progress.go

@@ -44,6 +44,14 @@ type OffboxProgress struct {
 	// in that case, so the page falls back to them.
 	FilesDone  int64 `json:"files_done"`
 	TotalFiles int64 `json:"total_files"`
+	// CurrentFile/ElapsedSec are the last resort, and on real data the most important fields here.
+	// restic 0.14 only counts a file into files_done/bytes_done when it COMPLETES, so a single
+	// dominant file freezes both counters: measured on the demo box, immich sat at files_done 1 of 46
+	// and bytes_done 0 for 42 seconds while restic worked on one ~430MB volume tar. No percentage can
+	// move during that window. What CAN be shown truthfully is which file is being processed and how
+	// long it has been going — "working on X, 42s" is a completely different message from "0%".
+	CurrentFile string `json:"current_file"`
+	ElapsedSec  int64  `json:"elapsed_sec"`
 }
 
 // resticStatusLine is the subset of restic's `--json` status object we consume. restic emits several
@@ -59,21 +67,25 @@ type OffboxProgress struct {
 // Note every numeric field except percent_done is `omitempty` on restic's side: a zero simply is not
 // in the JSON. That is why an incremental run reports no bytes_done at all rather than an explicit 0.
 type resticStatusLine struct {
-	MessageType string  `json:"message_type"`
-	PercentDone float64 `json:"percent_done"` // 0..1
-	TotalBytes  int64   `json:"total_bytes"`
-	BytesDone   int64   `json:"bytes_done"`
-	TotalFiles  int64   `json:"total_files"`
-	FilesDone   int64   `json:"files_done"`
+	MessageType    string   `json:"message_type"`
+	PercentDone    float64  `json:"percent_done"` // 0..1
+	TotalBytes     int64    `json:"total_bytes"`
+	BytesDone      int64    `json:"bytes_done"`
+	TotalFiles     int64    `json:"total_files"`
+	FilesDone      int64    `json:"files_done"`
+	CurrentFiles   []string `json:"current_files"`
+	SecondsElapsed int64    `json:"seconds_elapsed"`
 }
 
 // resticProgress is one parsed status line.
 type resticProgress struct {
-	Percent    float64 // 0..100
-	BytesDone  int64
-	TotalBytes int64
-	FilesDone  int64
-	TotalFiles int64
+	Percent     float64 // 0..100
+	BytesDone   int64
+	TotalBytes  int64
+	FilesDone   int64
+	TotalFiles  int64
+	CurrentFile string
+	ElapsedSec  int64
 }
 
 // parseResticStatus parses ONE line of restic --json output.
@@ -99,9 +111,14 @@ func parseResticStatus(line string) (resticProgress, bool) {
 	if pct > 100 {
 		pct = 100
 	}
+	cur := ""
+	if len(s.CurrentFiles) > 0 {
+		cur = s.CurrentFiles[0]
+	}
 	return resticProgress{
 		Percent: pct, BytesDone: s.BytesDone, TotalBytes: s.TotalBytes,
 		FilesDone: s.FilesDone, TotalFiles: s.TotalFiles,
+		CurrentFile: cur, ElapsedSec: s.SecondsElapsed,
 	}, true
 }
 
@@ -135,6 +152,7 @@ func (p *offboxProgressState) setApp(app string) {
 		p.cur.CurrentApp = app
 		p.cur.Percent, p.cur.BytesDone, p.cur.TotalBytes = 0, 0, 0
 		p.cur.FilesDone, p.cur.TotalFiles = 0, 0
+		p.cur.CurrentFile, p.cur.ElapsedSec = "", 0
 		p.cur.DoneHuman, p.cur.TotalHuman = "", ""
 	}
 	p.mu.Unlock()
@@ -145,6 +163,12 @@ func (p *offboxProgressState) update(r resticProgress) {
 	if p.live {
 		p.cur.Percent, p.cur.BytesDone, p.cur.TotalBytes = r.Percent, r.BytesDone, r.TotalBytes
 		p.cur.FilesDone, p.cur.TotalFiles = r.FilesDone, r.TotalFiles
+		p.cur.ElapsedSec = r.ElapsedSec
+		// Keep the last KNOWN current file: restic omits current_files on some status ticks, and
+		// blanking the label every other second is its own kind of flicker.
+		if r.CurrentFile != "" {
+			p.cur.CurrentFile = r.CurrentFile
+		}
 		p.cur.DoneHuman, p.cur.TotalHuman = humanizeBytes(r.BytesDone), humanizeBytes(r.TotalBytes)
 	}
 	p.mu.Unlock()