Add model catalog with specifications for DA3 and MoGe-2 models

- Introduced ModelSpec dataclass to define model attributes.
- Added multiple models including DA3 Small, Base, Giant 1.1, Nested Giant Large 1.1, and MoGe-2 variants.
- Implemented functions to retrieve model details and metadata.
- Included BEN2 model specifications for background removal.

src/snapform/server/model_download.py

@@ -15,12 +15,13 @@ from urllib.request import (
 
 HF_ENDPOINT = "https://huggingface.co"
 R2_ENDPOINT = "https://models.omoolab.xyz"
-CONNECT_TIMEOUT = 3.0
+CONNECT_TIMEOUT = 10.0
+READ_TIMEOUT = 60.0
 DOWNLOAD_CHUNK_SIZE = 256 * 1024
 
 
 class _ShortConnectHTTPSConnection(http.client.HTTPSConnection):
-    """Use a short timeout for connection setup, without limiting downloads."""
+    """Bound connection and idle reads without limiting total download time."""
 
     def connect(self):
         try:
@@ -28,7 +29,7 @@ class _ShortConnectHTTPSConnection(http.client.HTTPSConnection):
             super().connect()
         finally:
             self.timeout = None
-        self.sock.settimeout(None)
+        self.sock.settimeout(READ_TIMEOUT)
 
 
 class _ShortConnectHTTPSHandler(HTTPSHandler):