The first five minutes, as the product and not as a developer's first run

The first launch was a code box with a link under it, then an empty
Live screen with 'No cameras' in amber in a far corner, then a form
asking for an IP address, and for the first few minutes of all of it
the engine silently downloading 275 MB with nothing on screen but a
stopped-looking status. Walked in a browser with the new mock; nobody
who was not an installer would have got through it.

Now: a welcome that asks the one question a shop owner can answer -
managed from a head office, or on this PC only - with each path in a
sentence; a Getting Started checklist on Live that reads its three steps
from the engine and ticks them itself (recognition ready, camera added
and connected, camera proven by a walk-past), with the one button for
the next step, and that disappears the moment somebody is recognised;
and the model download reported as a percentage in the tray, the
sidebar and the checklist, parsed by the supervisor from the engine's
own progress lines.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KGcjxF1cNLcuwc3DAPcnfj

behavision/model_assets.py

@@ -35,6 +35,31 @@ _COPY_MAP = {
 }
 
 
+def _fetch(url: str, dest: Path, label: str) -> None:
+    """Download with progress on stdout the supervisor can read.
+
+    On first run this is minutes of nothing: the API is not up yet, so the
+    app cannot ask the engine what it is doing, and a shop PC that shows a
+    stopped engine for five minutes after install looks broken. The
+    supervisor watches for `download: <label> <n>%` and puts the number in
+    the tray and the window. Logged every 5 points, not every chunk, so the
+    log file does not fill with a progress bar.
+    """
+    last = -5
+
+    def hook(blocks: int, block_size: int, total: int) -> None:
+        nonlocal last
+        if total <= 0:
+            return
+        pct = min(100, blocks * block_size * 100 // total)
+        if pct >= last + 5:
+            last = pct
+            log.info("download: %s %d%%", label, pct)
+
+    urllib.request.urlretrieve(url, dest, hook)
+    log.info("download: %s 100%%", label)
+
+
 def setup_models(models_dir: Path) -> "list[str]":
     """Ensure all model files exist in models_dir. Returns missing ones."""
     models_dir = Path(models_dir)
@@ -44,7 +69,7 @@ def setup_models(models_dir: Path) -> "list[str]":
     if not yunet.exists():
         log.info("downloading YuNet face detector (~230 KB)...")
         tmp = yunet.with_suffix(".part")
-        urllib.request.urlretrieve(YUNET_URL, tmp)
+        _fetch(YUNET_URL, tmp, "face detector")
         tmp.rename(yunet)
         log.info("YuNet saved to %s", yunet)
 
@@ -88,7 +113,7 @@ def setup_models(models_dir: Path) -> "list[str]":
             import zipfile
 
             tmp = models_dir / "buffalo_l.zip.part"
-            urllib.request.urlretrieve(BUFFALO_L_URL, tmp)
+            _fetch(BUFFALO_L_URL, tmp, "recognition models")
             with zipfile.ZipFile(tmp) as zf:
                 for name, target in wanted.items():
                     member = next((n for n in zf.namelist()