ci: add incremental strict type gate

mypy.ini

@@ -0,0 +1,19 @@
+[mypy]
+python_version = 3.12
+strict = True
+warn_unused_configs = True
+ignore_missing_imports = True
+follow_imports = skip
+show_error_codes = True
+pretty = True
+files =
+    app/domain/episode.py,
+    app/domain/media.py,
+    app/domain/torrent.py,
+    app/domain/meta/infopath.py,
+    app/runtime/correlation.py,
+    app/runtime/observability/__init__.py,
+    app/runtime/event/contracts.py,
+    app/runtime/extensions/module/contracts.py,
+    app/startup/context.py,
+    app/api/context.py