feat: add desktop document search and verified native CPU embeddings

tools/semantic-proof/download.py

@@ -0,0 +1,53 @@
+"""Explicit provisioning only; inference never imports this downloader."""
+import argparse
+import hashlib
+import json
+import os
+from pathlib import Path
+import urllib.request
+
+HERE = Path(__file__).resolve().parent
+
+
+def digest(path):
+    with path.open("rb") as source:
+        return hashlib.file_digest(source, "sha256").hexdigest()
+
+
+def verified(path, spec):
+    return path.is_file() and path.stat().st_size == spec["bytes"] and digest(path) == spec["sha256"]
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Explicitly download ~136 MB of pinned, verified model artifacts")
+    parser.add_argument("--model-dir", type=Path, default=HERE / "model")
+    args = parser.parse_args()
+    manifest = json.loads((HERE / "model-manifest.json").read_text())
+    for spec in manifest["files"]:
+        target = args.model_dir / spec["path"]
+        if verified(target, spec):
+            print(f"Verified existing {spec['path']}")
+            continue
+        target.parent.mkdir(parents=True, exist_ok=True)
+        temporary = target.with_suffix(target.suffix + ".part")
+        url = f"https://huggingface.co/{manifest['model_id']}/resolve/{manifest['revision']}/{spec['path']}"
+        print(f"Downloading {spec['path']} ({spec['bytes']} bytes)", flush=True)
+        try:
+            request = urllib.request.Request(url, headers={"User-Agent": "Searchi-semantic-proof/0.1"})
+            with urllib.request.urlopen(request, timeout=60) as response, temporary.open("wb") as output:
+                total = 0
+                while chunk := response.read(1024 * 1024):
+                    total += len(chunk)
+                    if total > spec["bytes"]:
+                        raise ValueError("Download exceeds manifest size")
+                    output.write(chunk)
+            if not verified(temporary, spec):
+                raise ValueError(f"Size or SHA256 mismatch for {spec['path']}")
+            os.replace(temporary, target)
+            print(f"Verified SHA256 {spec['sha256']}")
+        finally:
+            temporary.unlink(missing_ok=True)
+
+
+if __name__ == "__main__":
+    main()