fix(deps): restore CI under SQLAlchemy 2.1

SQLAlchemy 2.1 no longer installs greenlet by default, so the async
engine fails to import (Test, E2E api container), and its sources use
the `untyped-decorator` mypy code that the pinned mypy 1.9 hook rejects
(Lint).

- depend on sqlalchemy[asyncio] so greenlet is installed again
- bump the mirrors-mypy pre-commit hook to v2.4.0
- guard nullable tag values / channel_idx flagged by the newer mypy

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UFsp2i9E98EzovBaurmtEb

.pre-commit-config.yaml

@@ -29,14 +29,14 @@ repos:
           - flake8-comprehensions
 
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.9.0
+    rev: v2.4.0
     hooks:
       - id: mypy
         exclude: ^alembic/
         additional_dependencies:
           - pydantic>=2.0.0
           - pydantic-settings>=2.0.0
-          - sqlalchemy>=2.0.0
+          - sqlalchemy[asyncio]>=2.0.0
           - fastapi>=0.100.0
           - alembic>=1.7.0
           - types-paho-mqtt>=1.6.0

pyproject.toml

@@ -28,7 +28,7 @@ dependencies = [
     "pydantic>=2.0.0",
     "pydantic-settings>=2.0.0",
     "python-dotenv>=1.0.0",
-    "sqlalchemy>=2.0.0",
+    "sqlalchemy[asyncio]>=2.0.0",
     "alembic>=1.12.0",
     "fastapi>=0.100.0",
     "starlette>=0.40.0,<1.0.0",

src/meshcore_hub/api/observer_utils.py

@@ -84,7 +84,8 @@ def fetch_observers_for_events(
             .where(NodeTag.key == "name")
         )
         for node_id, value in session.execute(tag_query).all():
-            tag_names[node_id] = value
+            if value is not None:
+                tag_names[node_id] = value
 
     for row in results:
         if row.event_hash not in observers_by_hash:
@@ -150,6 +151,7 @@ def resolve_sender_names(
         .where(NodeTag.key == "name")
     )
     for public_key, value in session.execute(tag_query).all():
-        tag_names[public_key[:12]] = value
+        if value is not None:
+            tag_names[public_key[:12]] = value
 
     return names, tag_names

src/meshcore_hub/api/routes/dashboard.py

@@ -217,7 +217,9 @@ def get_stats(
     )
     channel_results = session.execute(channel_counts_query).all()
     channel_message_counts = {
-        int(channel): int(count) for channel, count in channel_results
+        int(channel): int(count)
+        for channel, count in channel_results
+        if channel is not None
     }
 
     from meshcore_hub.common.config import get_web_settings
@@ -325,7 +327,8 @@ def get_recent_activity(
             .where(NodeTag.key == "name")
         )
         for public_key, value in session.execute(tag_name_query).all():
-            tag_names[public_key] = value
+            if value is not None:
+                tag_names[public_key] = value
 
     # Batch-resolve observers (via event_observers) and the legacy
     # observed_by public key for the recent adverts, mirroring the