diff --git a/assistant_bot/handlers.py b/assistant_bot/handlers.py
index 3ba4b4b..4c24099 100644
--- a/assistant_bot/handlers.py
+++ b/assistant_bot/handlers.py
@@ -148,16 +148,18 @@ async def private_voice(update: Update, context: ContextTypes.DEFAULT_TYPE) -> N
     )
     status_message = await update.message.reply_text("Распознаю голосовое сообщение...")
     temp_path: Path | None = None
+    transcript = ""
 
     try:
         telegram_file = await context.bot.get_file(voice.file_id)
         file_descriptor, raw_path = tempfile.mkstemp(suffix=".ogg")
         os.close(file_descriptor)
-        temp_path = Path(raw_path)
-        await telegram_file.download_to_drive(custom_path=temp_path)
+        voice_path = Path(raw_path)
+        temp_path = voice_path
+        await telegram_file.download_to_drive(custom_path=voice_path)
         transcript = await asyncio.to_thread(
             get_speech_recognizer(context).transcribe,
-            temp_path,
+            voice_path,
         )
     except (SpeechRecognitionError, TelegramError):
         logger.exception("Failed to transcribe Telegram voice message")
@@ -364,7 +366,7 @@ async def remind_command(update: Update, context: ContextTypes.DEFAULT_TYPE) ->
 
     reminder_id = get_storage(context).add_reminder(
         user_id=user_id,
-        chat_id=int(update.effective_chat.id),
+        chat_id=int(update.message.chat_id),
         text=parsed.text,
         remind_at_utc=parsed.remind_at_utc,
     )
diff --git a/assistant_bot/speech.py b/assistant_bot/speech.py
index 4a9e58a..15f59a9 100644
--- a/assistant_bot/speech.py
+++ b/assistant_bot/speech.py
@@ -2,7 +2,7 @@ import sys
 import threading
 import warnings
 from pathlib import Path
-from typing import Any, Callable, Protocol
+from typing import Any, Callable, Protocol, cast
 
 
 class SpeechRecognitionError(RuntimeError):
@@ -21,9 +21,9 @@ def load_whisper_model_class() -> Any:
     missing = object()
     loaded_torch = sys.modules.get("torch", missing)
     if loaded_torch is missing:
-        sys.modules["torch"] = None
+        sys.modules["torch"] = cast(Any, None)
     try:
-        with warnings.catch_warnings():
+        with warnings.catch_warnings(record=False):
             warnings.filterwarnings(
                 "ignore",
                 message="pkg_resources is deprecated as an API.*",
diff --git a/assistant_bot/storage.py b/assistant_bot/storage.py
index edb9232..43c5670 100644
--- a/assistant_bot/storage.py
+++ b/assistant_bot/storage.py
@@ -9,6 +9,17 @@ from .config import get_default_model
 from .time_utils import to_utc_iso, utc_now
 
 
+def row_to_dict(row: sqlite3.Row) -> dict[str, Any]:
+    return {str(key): row[key] for key in row.keys()}
+
+
+def required_lastrowid(cursor: sqlite3.Cursor) -> int:
+    lastrowid = cursor.lastrowid
+    if lastrowid is None:
+        raise RuntimeError("SQLite insert did not return a row ID")
+    return lastrowid
+
+
 class AssistantStorage:
     def __init__(self, path: Path) -> None:
         self.path = path
@@ -162,7 +173,7 @@ class AssistantStorage:
                 """,
                 (user_id, chat_id, started_after_id, limit),
             ).fetchall()
-        return [dict(row) for row in reversed(rows)]
+        return [row_to_dict(row) for row in reversed(rows)]
 
     def start_new_conversation(self, user_id: int, chat_id: int) -> None:
         now = to_utc_iso(utc_now())
@@ -230,7 +241,7 @@ class AssistantStorage:
             age = max(0, newest_id - int(row["id"]))
             recency_weight = 1.0 / (1.0 + age / 50.0)
             score = (coverage + phrase_bonus) * (0.5 + 0.5 * recency_weight)
-            item = dict(row)
+            item = row_to_dict(row)
             item["score"] = round(score, 4)
             matches.append((score, item))
 
@@ -266,7 +277,7 @@ class AssistantStorage:
                 (user_id, chat_id, message_id, radius),
             ).fetchall()
         rows = [*reversed(before), *after]
-        return [dict(row) for row in rows]
+        return [row_to_dict(row) for row in rows]
 
     def get_user_model(self, user_id: int, provider: str = "local") -> str:
         column = self._model_column(provider)
@@ -315,7 +326,7 @@ class AssistantStorage:
                 "INSERT INTO memories(user_id, text, created_at) VALUES (?, ?, ?)",
                 (user_id, text, to_utc_iso(utc_now())),
             )
-            return int(cursor.lastrowid)
+            return required_lastrowid(cursor)
 
     def list_memories(self, user_id: int, limit: int = 20) -> list[dict[str, Any]]:
         with self._connection() as connection:
@@ -329,7 +340,7 @@ class AssistantStorage:
                 """,
                 (user_id, limit),
             ).fetchall()
-        return [dict(row) for row in rows]
+        return [row_to_dict(row) for row in rows]
 
     def delete_memory(self, user_id: int, memory_id: int) -> bool:
         with self._connection() as connection:
@@ -345,7 +356,7 @@ class AssistantStorage:
                 "INSERT INTO notes(user_id, text, created_at) VALUES (?, ?, ?)",
                 (user_id, text, to_utc_iso(utc_now())),
             )
-            return int(cursor.lastrowid)
+            return required_lastrowid(cursor)
 
     def list_notes(self, user_id: int, limit: int = 20) -> list[dict[str, Any]]:
         with self._connection() as connection:
@@ -359,7 +370,7 @@ class AssistantStorage:
                 """,
                 (user_id, limit),
             ).fetchall()
-        return [dict(row) for row in rows]
+        return [row_to_dict(row) for row in rows]
 
     def delete_note(self, user_id: int, note_id: int) -> bool:
         with self._connection() as connection:
@@ -390,7 +401,7 @@ class AssistantStorage:
                     to_utc_iso(utc_now()),
                 ),
             )
-            return int(cursor.lastrowid)
+            return required_lastrowid(cursor)
 
     def list_reminders(self, user_id: int, limit: int = 20) -> list[dict[str, Any]]:
         with self._connection() as connection:
@@ -404,7 +415,7 @@ class AssistantStorage:
                 """,
                 (user_id, limit),
             ).fetchall()
-        return [dict(row) for row in rows]
+        return [row_to_dict(row) for row in rows]
 
     def cancel_reminder(self, user_id: int, reminder_id: int) -> bool:
         with self._connection() as connection:
@@ -430,7 +441,7 @@ class AssistantStorage:
                 """,
                 (to_utc_iso(now_utc), limit),
             ).fetchall()
-        return [dict(row) for row in rows]
+        return [row_to_dict(row) for row in rows]
 
     def mark_reminder_sent(self, reminder_id: int) -> None:
         with self._connection() as connection:
@@ -453,7 +464,7 @@ class AssistantStorage:
                 """,
                 (user_id, title, status, now, now),
             )
-            return int(cursor.lastrowid)
+            return required_lastrowid(cursor)
 
     def list_tracked_items(self, user_id: int, limit: int = 30) -> list[dict[str, Any]]:
         with self._connection() as connection:
@@ -467,7 +478,7 @@ class AssistantStorage:
                 """,
                 (user_id, limit),
             ).fetchall()
-        return [dict(row) for row in rows]
+        return [row_to_dict(row) for row in rows]
 
     def set_tracked_status(self, user_id: int, item_id: int, status: str) -> bool:
         with self._connection() as connection:
diff --git a/assistant_bot/telegram_utils.py b/assistant_bot/telegram_utils.py
index 31e9351..6155a3d 100644
--- a/assistant_bot/telegram_utils.py
+++ b/assistant_bot/telegram_utils.py
@@ -57,12 +57,13 @@ def get_voice_max_duration(context: ContextTypes.DEFAULT_TYPE) -> int:
 
 
 def command_text(context: ContextTypes.DEFAULT_TYPE) -> str:
-    return " ".join(context.args).strip()
+    return " ".join(context.args or []).strip()
 
 
 def require_user_id(update: Update) -> int | None:
-    if update.effective_user:
-        return int(update.effective_user.id)
+    user = update.effective_user
+    if user:
+        return int(user.id)
     return None
 
 
diff --git a/tests/test_core.py b/tests/test_core.py
index 4c0d91e..05c6436 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -13,7 +13,10 @@ from assistant_bot.storage import AssistantStorage
 
 class ReminderParserTests(unittest.TestCase):
     def test_supported_relative_unit(self) -> None:
-        self.assertEqual(unit_to_timedelta(2, "часа").total_seconds(), 7200)
+        delta = unit_to_timedelta(2, "часа")
+        self.assertIsNotNone(delta)
+        assert delta is not None
+        self.assertEqual(delta.total_seconds(), 7200)
 
     def test_absolute_datetime(self) -> None:
         result = parse_reminder(
diff --git a/tests/test_jobs.py b/tests/test_jobs.py
index 1fb766d..64d682c 100644
--- a/tests/test_jobs.py
+++ b/tests/test_jobs.py
@@ -1,6 +1,7 @@
 import asyncio
 import unittest
 from types import SimpleNamespace
+from typing import Any
 from unittest.mock import patch
 
 from assistant_bot.jobs import post_init, post_shutdown
@@ -10,11 +11,11 @@ class ReminderJobLifecycleTests(unittest.IsolatedAsyncioTestCase):
     async def test_reminder_task_is_cancelled_on_shutdown(self) -> None:
         started = asyncio.Event()
 
-        async def fake_reminder_loop(application) -> None:
+        async def fake_reminder_loop(_application) -> None:
             started.set()
             await asyncio.Event().wait()
 
-        application = SimpleNamespace(bot_data={})
+        application: Any = SimpleNamespace(bot_data={})
         with patch("assistant_bot.jobs.reminder_loop", fake_reminder_loop):
             await post_init(application)
             await started.wait()
diff --git a/tests/test_voice_handler.py b/tests/test_voice_handler.py
index 1b9d4e4..8e8bbee 100644
--- a/tests/test_voice_handler.py
+++ b/tests/test_voice_handler.py
@@ -1,6 +1,7 @@
 import unittest
 from pathlib import Path
 from types import SimpleNamespace
+from typing import Any
 from unittest.mock import AsyncMock, MagicMock, patch
 
 from assistant_bot.handlers import private_voice
@@ -15,7 +16,7 @@ class VoiceHandlerTests(unittest.IsolatedAsyncioTestCase):
             voice=SimpleNamespace(duration=duration, file_id="voice-file-id"),
             reply_text=AsyncMock(return_value=status_message),
         )
-        update = SimpleNamespace(message=message)
+        update: Any = SimpleNamespace(message=message)
         telegram_file = SimpleNamespace(download_to_drive=AsyncMock())
         bot = SimpleNamespace(
             get_file=AsyncMock(return_value=telegram_file),
@@ -23,7 +24,7 @@ class VoiceHandlerTests(unittest.IsolatedAsyncioTestCase):
         )
         recognizer = MagicMock()
         recognizer.transcribe.return_value = transcript
-        context = SimpleNamespace(
+        context: Any = SimpleNamespace(
             bot=bot,
             application=SimpleNamespace(
                 bot_data={
diff --git a/tests/test_yandex_ai.py b/tests/test_yandex_ai.py
index e8d98b5..12877d1 100644
--- a/tests/test_yandex_ai.py
+++ b/tests/test_yandex_ai.py
@@ -38,6 +38,15 @@ class FakeChatCompletions:
         return self.completion
 
 
+class FakeHTTPError(RuntimeError):
+    def __init__(self) -> None:
+        super().__init__("forbidden")
+        self.response = SimpleNamespace(
+            status_code=403,
+            text='{"error":{"message":"folder mismatch"}}',
+        )
+
+
 class YandexAIClientTests(unittest.IsolatedAsyncioTestCase):
     def test_multiple_system_messages_are_merged_at_the_beginning(self) -> None:
         self.assertEqual(
@@ -62,11 +71,7 @@ class YandexAIClientTests(unittest.IsolatedAsyncioTestCase):
         )
 
     def test_http_error_includes_safe_response_body(self) -> None:
-        error = RuntimeError("forbidden")
-        error.response = SimpleNamespace(
-            status_code=403,
-            text='{"error":{"message":"folder mismatch"}}',
-        )
+        error = FakeHTTPError()
 
         self.assertEqual(
             describe_yandex_error(error),