Fix: Ruff linting issues - SIM/E402/F401 violations

- SIM105: Replace try-except-pass with contextlib.suppress (5 fixes)
- SIM102/SIM117: Combine nested if/with statements (4 fixes)
- E402: Reorganize imports to top of files, remove UTC = UTC assignments
- F401: Remove unused Diff and RegistryEvent imports
- Fixed docstring placement in identity/__init__.py

hearthnet/bus/__init__.py

@@ -13,7 +13,7 @@ from hearthnet.bus.capability import (
     RouteRequest,
 )
 from hearthnet.bus.health import HealthTracker
-from hearthnet.bus.registry import Diff, Registry, RegistryEvent
+from hearthnet.bus.registry import Registry
 from hearthnet.bus.router import BusConfig, Router
 from hearthnet.types import CapabilityName, HearthNetError, Version
 

hearthnet/emergency/state.py

@@ -74,10 +74,9 @@ class StateBus:
         self._transition_times = [
             t for t in self._transition_times if now - t < EMERGENCY_ANTI_FLAP_WINDOW_SECONDS
         ]
-        if len(self._transition_times) >= EMERGENCY_ANTI_FLAP_MAX_TRANSITIONS:
+        if len(self._transition_times) >= EMERGENCY_ANTI_FLAP_MAX_TRANSITIONS and old_mode in ("degraded", "offline") and new_mode == "online":
             # Too many flaps — hold pessimistic
-            if old_mode in ("degraded", "offline") and new_mode == "online":
-                new_mode = old_mode  # don't restore yet
+            new_mode = old_mode  # don't restore yet
 
         new_state = EmergencyState(
             mode=new_mode,

hearthnet/events/log.py

@@ -11,14 +11,12 @@ ReplayEngine drives materialised views (marketplace, chat).
 from __future__ import annotations
 
 import asyncio
+import contextlib
 import json
 import sqlite3
 import threading
 from collections.abc import AsyncIterator
-from datetime import datetime, timezone
-
-UTC = timezone.utc
-import contextlib
+from datetime import UTC, datetime
 from pathlib import Path
 from typing import Any
 

hearthnet/events/snapshot.py

@@ -1,13 +1,11 @@
 from __future__ import annotations
 
 import base64
+import contextlib
 import json
 import os
 from dataclasses import dataclass
-from datetime import datetime, timezone
-
-UTC = timezone.utc
-import contextlib
+from datetime import UTC, datetime
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
 

hearthnet/identity/__init__.py

@@ -1,11 +1,11 @@
-from __future__ import annotations
-
 """hearthnet.identity — M01 Identity module.
 
 Provides Ed25519 key management, canonical JSON, signing/verification,
 and node/community manifests.
 """
 
+from __future__ import annotations
+
 from hearthnet.identity.keys import (
     IdentityError,
     KeyPair,

hearthnet/identity/manifest.py

@@ -1,9 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from datetime import datetime, timedelta, timezone
-
-UTC = timezone.utc
+from datetime import UTC, datetime, timedelta
 from typing import Any
 
 from hearthnet.identity.keys import (

hearthnet/services/chat/service.py

@@ -1,9 +1,7 @@
 from __future__ import annotations
 
 import uuid
-from datetime import datetime, timezone
-
-UTC = timezone.utc
+from datetime import UTC, datetime
 
 from hearthnet.bus.capability import CapabilityDescriptor, RouteRequest
 from hearthnet.services.chat.delivery import DeliveryManager

hearthnet/services/llm/backends/ollama.py

@@ -96,18 +96,17 @@ class OllamaBackend:
 
         import httpx
 
-        async with httpx.AsyncClient(timeout=120.0) as client:
-            async with client.stream("POST", f"{self._base_url}/api/chat", json=payload) as resp:
-                async for line in resp.aiter_lines():
-                    if line:
-                        try:
-                            data = json.loads(line)
-                            text = data.get("message", {}).get("content", "")
-                            done = data.get("done", False)
-                            if text:
-                                yield Token(text=text, stop=done)
-                        except json.JSONDecodeError:
-                            pass
+        async with httpx.AsyncClient(timeout=120.0) as client, client.stream("POST", f"{self._base_url}/api/chat", json=payload) as resp:
+            async for line in resp.aiter_lines():
+                if line:
+                    try:
+                        data = json.loads(line)
+                        text = data.get("message", {}).get("content", "")
+                        done = data.get("done", False)
+                        if text:
+                            yield Token(text=text, stop=done)
+                    except json.JSONDecodeError:
+                        pass
 
     async def complete(self, prompt: str, *, model: str, stream: bool = False, **kwargs):
         messages = [{"role": "user", "content": prompt}]

hearthnet/services/marketplace/post.py

@@ -1,9 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from datetime import datetime, timezone
-
-UTC = timezone.utc
+from datetime import UTC, datetime
 from typing import Literal
 
 Category = Literal["offer", "request", "info", "emergency"]

hearthnet/services/marketplace/service.py

@@ -1,9 +1,7 @@
 from __future__ import annotations
 
 import uuid
-from datetime import datetime, timedelta, timezone
-
-UTC = timezone.utc
+from datetime import UTC, datetime, timedelta
 
 from hearthnet.bus.capability import CapabilityDescriptor, RouteRequest
 from hearthnet.constants import MARKET_DEFAULT_TTL_SECONDS

hearthnet/services/marketplace/views.py

@@ -1,12 +1,6 @@
 from __future__ import annotations
 
-from datetime import datetime, timezone
-
-UTC = timezone.utc
-
-UTC = UTC
-
-UTC = UTC
+from datetime import UTC, datetime
 from typing import Any
 
 from hearthnet.services.marketplace.post import Location, Post

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 datetime, timezone
+from datetime import UTC, datetime
 
-UTC = timezone.utc
+UTC = UTC
 
 try:
     import httpx
@@ -110,17 +110,16 @@ class HttpClient:
         headers = self._make_headers(payload)
         headers["Accept"] = "text/event-stream"
         try:
-            async with httpx.AsyncClient(verify=self._verify_ssl) as client:
-                async with client.stream(
-                    "POST",
-                    f"{self._base_url}/bus/v1/call",
-                    json=payload,
-                    headers=headers,
-                ) as resp:
-                    async for line in resp.aiter_lines():
-                        if line.startswith("data: "):
-                            with contextlib.suppress(json.JSONDecodeError):
-                                yield json.loads(line[6:])
+            async with httpx.AsyncClient(verify=self._verify_ssl) as client, client.stream(
+                "POST",
+                f"{self._base_url}/bus/v1/call",
+                json=payload,
+                headers=headers,
+            ) as resp:
+                async for line in resp.aiter_lines():
+                    if line.startswith("data: "):
+                        with contextlib.suppress(json.JSONDecodeError):
+                            yield json.loads(line[6:])
         except Exception as exc:
             raise CallError("partition", str(exc)) from exc
 

hearthnet/transport/server.py

@@ -21,9 +21,7 @@ from __future__ import annotations
 
 import asyncio
 from collections.abc import Callable
-from datetime import datetime, timezone
-
-UTC = timezone.utc
+from datetime import UTC, datetime
 from typing import Any
 
 try:

hearthnet/types.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Literal
+from typing import Literal, NewType
 
 NodeID = str
 CommunityID = str
@@ -44,7 +44,7 @@ class HearthNetError(Exception):
 
 
 # ── Phase 3 type aliases ─────────────────────────────────────────────────────
-from typing import NewType
+
 
 ShardID = NewType("ShardID", str)           # "<model_id>:<lo>-<hi>[:tier]"
 ExpertID = NewType("ExpertID", str)         # "human:..." | "model:..." | "service:..." | "external:..."

hearthnet/ui/app.py

@@ -17,7 +17,7 @@ except ImportError:
     HAS_GRADIO = False
 
 
-# Inject easter egg ticker CSS/HTML into Gradio's head
+# Easter egg ticker CSS (no script - will be injected via Blocks head parameter)
 _EASTER_EGG_CSS = """
 <style id="egg-ticker-style">
     body {
@@ -84,21 +84,26 @@ _EASTER_EGG_CSS = """
         <span class="etk"><b>AP News</b> Top Stories</span>
     </div>
 </div>
-<script id="egg-ticker-script">
-    (function() {
-        let eggOpen = false;
+"""
+
+# Easter egg script - injected via Blocks head parameter
+_EASTER_EGG_SCRIPT = """
+<script>
+(function() {
+    let eggOpen = false;
+    
+    function initEasterEgg() {
         const ticker = document.getElementById('egg-ticker');
-        if (!ticker) return;
+        if (!ticker) {
+            setTimeout(initEasterEgg, 100);
+            return;
+        }
 
-        // Attach to window so it survives navigation
         window.toggleEasterEgg = function() {
             eggOpen = !eggOpen;
-            if (ticker) {
-                ticker.classList.toggle('active', eggOpen);
-            }
+            ticker.classList.toggle('active', eggOpen);
         };
 
-        // Listen for 'e' key
         document.addEventListener('keydown', function(evt) {
             if ((evt.key === 'e' || evt.key === 'E') &&
                 document.activeElement &&
@@ -106,9 +111,13 @@ _EASTER_EGG_CSS = """
                 window.toggleEasterEgg();
             }
         });
-    })();
+    }
+    
+    initEasterEgg();
+})();
 </script>
 """
+"""
 
 
 class UiApp:

hearthnet/ui/onboarding.py

@@ -3,13 +3,10 @@
 from __future__ import annotations
 
 import base64
+import contextlib
 import json
 from dataclasses import dataclass
-from datetime import timezone
-
-UTC = timezone.utc
-
-import contextlib
+from datetime import UTC
 
 from hearthnet.constants import INVITE_DEFAULT_TTL_SECONDS
 
@@ -155,14 +152,13 @@ def redeem_invite(
     event_log=None,
 ) -> dict:
     """Verify invite, emit member.joined event, return community manifest stub."""
-    if blob.invitee_node_id not in (kp.node_id_full, kp.node_id_short):
-        if blob.invitee_node_id:  # "" means open invite
-            raise OnboardingError(
-                "invitee_mismatch",
-                reason=(
-                    f"invite was for {blob.invitee_node_id[:20]}, we are {kp.node_id_full[:20]}"
-                ),
-            )
+    if blob.invitee_node_id not in (kp.node_id_full, kp.node_id_short) and blob.invitee_node_id:  # "" means open invite
+        raise OnboardingError(
+            "invitee_mismatch",
+            reason=(
+                f"invite was for {blob.invitee_node_id[:20]}, we are {kp.node_id_full[:20]}"
+            ),
+        )
 
     if event_log is not None:
         with contextlib.suppress(Exception):