feat(tagger): real byte progress for model download instead of a spinner

The 1.3 GB model.onnx downloaded via hf-hub's repo.get() and the ONNX
runtime DLLs via a read_to_end — neither reported bytes, so the user saw
only an indeterminate spinner on a multi-minute download.

- tagger model files now download via repo.download_with_progress with a
  HubProgress adapter over hf-hub's Progress trait (throttled 200ms events
  carrying downloaded/total bytes)
- captioner's nuget DLL download streams in 64 KB chunks, parsing
  content-length, and reports per-chunk byte progress
- TaggerModelProgress carries downloaded_bytes/total_bytes; onboarding and
  Settings show a determinate bar plus 'X MB / Y MB' for the current file

src/components/SettingsModal.tsx

@@ -9,6 +9,12 @@ const SECTIONS: { id: SettingsSection; label: string; detail: string }[] = [
   { id: "general", label: "General", detail: "App data and diagnostics" },
 ];
 
+function formatBytesShort(bytes: number): string {
+  if (bytes >= 1024 * 1024 * 1024) return `${(bytes / (1024 * 1024 * 1024)).toFixed(1)} GB`;
+  if (bytes >= 1024 * 1024) return `${(bytes / (1024 * 1024)).toFixed(0)} MB`;
+  return `${(bytes / 1024).toFixed(0)} KB`;
+}
+
 function StatusPill({ children, tone }: { children: React.ReactNode; tone: "ready" | "muted" | "busy" }) {
   const className =
     tone === "ready"
@@ -235,16 +241,24 @@ export function SettingsModal() {
         : "no folders selected";
   const thresholdDisplay = taggerThresholdDraft ?? String(taggerThreshold);
   const batchSizeDisplay = taggerBatchSizeDraft ?? String(taggerBatchSize);
-  const taggerDownloadLabel = taggerModelProgress
-    ? `Downloading ${taggerModelProgress.completed_files}/${taggerModelProgress.total_files}`
-    : taggerModelPreparing
-      ? "Preparing WD Tagger..."
-      : taggerReady
-        ? "Installed"
-        : "Install model";
-  const taggerDownloadPercent = taggerModelProgress
-    ? Math.round((taggerModelProgress.completed_files / Math.max(taggerModelProgress.total_files, 1)) * 100)
-    : 0;
+  const taggerBytesKnown =
+    taggerModelProgress?.downloaded_bytes != null &&
+    taggerModelProgress.total_bytes != null &&
+    taggerModelProgress.total_bytes > 0;
+  const taggerDownloadLabel = taggerBytesKnown
+    ? `Downloading ${formatBytesShort(taggerModelProgress!.downloaded_bytes!)} / ${formatBytesShort(taggerModelProgress!.total_bytes!)}`
+    : taggerModelProgress
+      ? `Downloading ${taggerModelProgress.completed_files}/${taggerModelProgress.total_files}`
+      : taggerModelPreparing
+        ? "Preparing WD Tagger..."
+        : taggerReady
+          ? "Installed"
+          : "Install model";
+  const taggerDownloadPercent = taggerBytesKnown
+    ? Math.round((taggerModelProgress!.downloaded_bytes! / taggerModelProgress!.total_bytes!) * 100)
+    : taggerModelProgress
+      ? Math.round((taggerModelProgress.completed_files / Math.max(taggerModelProgress.total_files, 1)) * 100)
+      : 0;
 
   const runQueueAction = (action: "queue" | "clear") => {
     const selectedIds = taggingQueueFolderIds;

src/components/onboarding/StepAiFeatures.tsx

@@ -1,9 +1,20 @@
 import { useEffect } from "react";
-import { useGalleryStore } from "../../store";
-import { FakeProgressBar } from "./fakes";
+import { TaggerModelProgress, useGalleryStore } from "../../store";
+import { FakeProgressBar, formatBytes } from "./fakes";
 
 const FAKE_TAGS = ["landscape", "sunset", "outdoors", "no_humans", "ocean", "cloudy_sky"];
 
+// Prefer the current file's byte fraction (the 1.3 GB model dominates); fall
+// back to the coarse step count; null renders an indeterminate bar.
+function taggerDownloadFraction(progress: TaggerModelProgress | null): number | null {
+  if (!progress) return null;
+  if (progress.downloaded_bytes != null && progress.total_bytes != null && progress.total_bytes > 0) {
+    return progress.downloaded_bytes / progress.total_bytes;
+  }
+  if (progress.total_files > 0) return progress.completed_files / progress.total_files;
+  return null;
+}
+
 export function StepAiFeatures() {
   const taggerModelStatus = useGalleryStore((s) => s.taggerModelStatus);
   const taggerModelPreparing = useGalleryStore((s) => s.taggerModelPreparing);
@@ -61,16 +72,15 @@ export function StepAiFeatures() {
           </div>
           {taggerModelPreparing ? (
             <div className="mt-3">
-              <FakeProgressBar
-                fraction={
-                  taggerModelProgress && taggerModelProgress.total_files > 0
-                    ? taggerModelProgress.completed_files / taggerModelProgress.total_files
-                    : null
-                }
-              />
-              {taggerModelProgress?.current_file ? (
-                <p className="mt-1.5 truncate text-[11px] text-gray-600">{taggerModelProgress.current_file}</p>
-              ) : null}
+              <FakeProgressBar fraction={taggerDownloadFraction(taggerModelProgress)} />
+              <div className="mt-1.5 flex items-center justify-between gap-3 text-[11px] text-gray-600">
+                <span className="truncate">{taggerModelProgress?.current_file ?? "Preparing..."}</span>
+                {taggerModelProgress?.downloaded_bytes != null && taggerModelProgress.total_bytes != null ? (
+                  <span className="shrink-0 tabular-nums">
+                    {formatBytes(taggerModelProgress.downloaded_bytes)} / {formatBytes(taggerModelProgress.total_bytes)}
+                  </span>
+                ) : null}
+              </div>
             </div>
           ) : null}
           {!taggerModelPreparing && taggerModelError ? (

src/store.ts

@@ -112,6 +112,8 @@ export interface TaggerModelProgress {
   total_files: number;
   completed_files: number;
   current_file: string | null;
+  downloaded_bytes: number | null;
+  total_bytes: number | null;
   done: boolean;
 }