fix: re-apply Python 3.10 UTC compatibility (was reverted by formatter)

The formatter reverted our UTC → timezone.utc changes.
Re-applied the fix across all 10 files to support Python 3.10 on HF Space.

Files fixed:
- hearthnet/services/chat/service.py
- hearthnet/events/snapshot.py
- hearthnet/events/log.py
- hearthnet/identity/manifest.py
- hearthnet/ui/onboarding.py
- hearthnet/transport/server.py
- hearthnet/transport/client.py
- hearthnet/services/marketplace/views.py
- hearthnet/services/marketplace/service.py
- hearthnet/services/marketplace/post.py

hearthnet/discovery/udp.py

@@ -117,10 +117,9 @@ class UdpListener:
         try:
             sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
             sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-            try:
+            from contextlib import suppress
+            with suppress(AttributeError, OSError):
                 sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)  # type: ignore[attr-defined]
-            except (AttributeError, OSError):
-                pass
             sock.bind(("", self._port))
             mcast_req = struct.pack("4sL", socket.inet_aton(UDP_MULTICAST_GROUP), socket.INADDR_ANY)
             sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mcast_req)

hearthnet/events/log.py

@@ -15,9 +15,9 @@ import json
 import sqlite3
 import threading
 from collections.abc import AsyncIterator
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 
-UTC = UTC
+UTC = timezone.utc
 import contextlib
 from pathlib import Path
 from typing import Any

hearthnet/events/snapshot.py

@@ -4,9 +4,9 @@ import base64
 import json
 import os
 from dataclasses import dataclass
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 
-UTC = UTC
+UTC = timezone.utc
 import contextlib
 from pathlib import Path
 from typing import TYPE_CHECKING, Any

hearthnet/identity/keys.py

@@ -245,10 +245,9 @@ def save(kp: KeyPair, keys_dir: Path) -> None:
     sk_bytes = bytes(kp.signing_key)
     priv_path.write_bytes(base64.urlsafe_b64encode(sk_bytes).rstrip(b"=") + b"\n")
     # Restrict permissions on POSIX
-    try:
+    from contextlib import suppress
+    with suppress(AttributeError):
         os.chmod(priv_path, stat.S_IRUSR | stat.S_IWUSR)  # 0600
-    except AttributeError:
-        pass  # Windows: chmod semantics differ; best-effort
     # Write public key
     vk_bytes = bytes(kp.verify_key)
     pub_path.write_bytes(base64.urlsafe_b64encode(vk_bytes).rstrip(b"=") + b"\n")

hearthnet/identity/manifest.py

@@ -1,9 +1,9 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from datetime import UTC, datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
-UTC = UTC
+UTC = timezone.utc
 from typing import Any
 
 from hearthnet.identity.keys import (

hearthnet/observability/otlp_export.py

@@ -159,13 +159,10 @@ class OtlpExporter:
 
     async def shutdown(self) -> None:
         """Flush and shut down the underlying providers."""
+        from contextlib import suppress
         if self._meter_provider is not None:
-            try:
+            with suppress(Exception):
                 self._meter_provider.shutdown()  # type: ignore[union-attr]
-            except Exception:
-                pass
         if self._tracer_provider is not None:
-            try:
+            with suppress(Exception):
                 self._tracer_provider.shutdown()  # type: ignore[union-attr]
-            except Exception:
-                pass

hearthnet/relay/client.py

@@ -204,8 +204,6 @@ class RelayClient:
             with contextlib.suppress(asyncio.CancelledError):
                 await self._keepalive_task
         if self._httpx_client is not None:
-            try:
+            with contextlib.suppress(Exception):
                 await self._httpx_client.aclose()  # type: ignore[union-attr]
-            except Exception:
-                pass
             self._httpx_client = None

hearthnet/relay/push_subscriber.py

@@ -100,9 +100,8 @@ class PushSubscriber:
 
     async def close(self) -> None:
         """Close the internal httpx client."""
+        from contextlib import suppress
         if self._httpx_client is not None:
-            try:
+            with suppress(Exception):
                 await self._httpx_client.aclose()  # type: ignore[union-attr]
-            except Exception:
-                pass
             self._httpx_client = None

hearthnet/services/chat/service.py

@@ -1,9 +1,9 @@
 from __future__ import annotations
 
 import uuid
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 
-UTC = UTC
+UTC = timezone.utc
 
 from hearthnet.bus.capability import CapabilityDescriptor, RouteRequest
 from hearthnet.services.chat.delivery import DeliveryManager

hearthnet/services/marketplace/post.py

@@ -1,9 +1,9 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 
-UTC = UTC
+UTC = timezone.utc
 from typing import Literal
 
 Category = Literal["offer", "request", "info", "emergency"]

hearthnet/services/marketplace/service.py

@@ -1,9 +1,9 @@
 from __future__ import annotations
 
 import uuid
-from datetime import UTC, datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
-UTC = UTC
+UTC = timezone.utc
 
 from hearthnet.bus.capability import CapabilityDescriptor, RouteRequest
 from hearthnet.constants import MARKET_DEFAULT_TTL_SECONDS

hearthnet/services/marketplace/views.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
-from datetime import UTC, datetime
+from datetime import datetime, timezone
+
+UTC = timezone.utc
 
 UTC = UTC
 

hearthnet/transport/client.py

@@ -7,9 +7,9 @@ import json
 import secrets
 from collections.abc import AsyncIterator
 from dataclasses import dataclass, field
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 
-UTC = UTC
+UTC = timezone.utc
 
 try:
     import httpx

hearthnet/transport/server.py

@@ -21,9 +21,9 @@ from __future__ import annotations
 
 import asyncio
 from collections.abc import Callable
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 
-UTC = UTC
+UTC = timezone.utc
 from typing import Any
 
 try:

hearthnet/ui/onboarding.py

@@ -5,9 +5,9 @@ from __future__ import annotations
 import base64
 import json
 from dataclasses import dataclass
-from datetime import UTC
+from datetime import timezone
 
-UTC = UTC
+UTC = timezone.utc
 
 import contextlib