diff --git a/mediahive/__main__.py b/mediahive/__main__.py
index 77915fe..88b5e8c 100644
--- a/mediahive/__main__.py
+++ b/mediahive/__main__.py
@@ -1,3 +1,5 @@
+"""MediaHive CLI entrypoint."""
+
 import argparse
 import asyncio
 import json
diff --git a/mediahive/hivescan/__main__.py b/mediahive/hivescan/__main__.py
index b841a46..2dd0d1b 100644
--- a/mediahive/hivescan/__main__.py
+++ b/mediahive/hivescan/__main__.py
@@ -1,3 +1,5 @@
+"""Hivescan CLI entrypoint."""
+
 import argparse
 import asyncio
 import json
diff --git a/mediahive/hivescan/indexer.py b/mediahive/hivescan/indexer.py
index 222032e..4fe4df6 100644
--- a/mediahive/hivescan/indexer.py
+++ b/mediahive/hivescan/indexer.py
@@ -383,7 +383,9 @@ async def _process_movies(
 ) -> AsyncIterator[tuple[Movie, tuple[str, Path, str] | None]]:
     """Async generator that processes all movies.
 
-    Yields (Movie, showreel_task_or_None) for each movie as it is processed.
+    Yields:
+        Tuples of ``(Movie, showreel_task_or_None)`` as each movie is processed.
+
     """
     # In-memory cache for TMDb lookups
     movie_tmdb_cache: dict[str, Info | None] = {}
@@ -555,7 +557,7 @@ async def _process_movies(
         yield movie, showreel_task
 
     # Process movies without TMDb info
-    for key, group_data in no_tmdb_movie_groups.items():
+    for group_data in no_tmdb_movie_groups.values():
         items = group_data["items"]
         title = group_data["title"]
         year = group_data["year"]
@@ -637,7 +639,9 @@ async def _process_series(
 ) -> AsyncIterator[tuple[Series, list[tuple[str, Path, int, int, str]]]]:
     """Async generator that processes all series.
 
-    Yields (Series, episode_reel_tasks) for each series as it is processed.
+    Yields:
+        Tuples of ``(Series, episode_reel_tasks)`` as each series is processed.
+
     """
     # In-memory cache for TMDb lookups
     series_tmdb_cache: dict[str, Info | None] = {}
@@ -787,7 +791,7 @@ async def _process_series(
         yield series, ep_reel_tasks
 
     # Process series without TMDb info
-    for key, group_data in no_tmdb_groups.items():
+    for group_data in no_tmdb_groups.values():
         items = group_data["items"]
         title = group_data["title"]
         content_hash = hashlib.md5(f"series:{title}".encode()).hexdigest()[:12]
diff --git a/mediahive/hivescan/scanner.py b/mediahive/hivescan/scanner.py
index 0dda546..79db2ca 100644
--- a/mediahive/hivescan/scanner.py
+++ b/mediahive/hivescan/scanner.py
@@ -162,8 +162,8 @@ class RootScanner:
                 )
             )
 
-        MEDIA_CONTAINER_DIRS = {"BDMV", "VIDEO_TS", "HVDVD_TS"}
-        VIDEO_EXTENSIONS = {
+        media_container_dirs = {"BDMV", "VIDEO_TS", "HVDVD_TS"}
+        video_extensions = {
             ".mkv",
             ".mp4",
             ".avi",
@@ -196,7 +196,7 @@ class RootScanner:
                         continue
 
                     if await AsyncPath(item).is_dir():
-                        if item.name.upper() in MEDIA_CONTAINER_DIRS:
+                        if item.name.upper() in media_container_dirs:
                             is_media_container = True
                         child_dirs.append(item)
                     else:
@@ -232,7 +232,7 @@ class RootScanner:
                     await _walk(child)
                     await asyncio.sleep(0)
                 for child_file in child_files:
-                    if child_file.suffix.lower() in VIDEO_EXTENSIONS:
+                    if child_file.suffix.lower() in video_extensions:
                         relpath = make_relative_path(str(child_file), media_root_str)
                         try:
                             stat_info = await AsyncPath(child_file).stat()
@@ -298,6 +298,7 @@ class RootScanner:
 
     async def _run_scan(self) -> None:
         """Full scan pipeline:
+
         1. Discover downloads
         2. Categorise → movies / series
         3. Iterate async generators, send each item as Upsert
diff --git a/mediahive/hivescan/tmdb_client.py b/mediahive/hivescan/tmdb_client.py
index c31a933..9deb8af 100644
--- a/mediahive/hivescan/tmdb_client.py
+++ b/mediahive/hivescan/tmdb_client.py
@@ -411,8 +411,8 @@ async def fetch_movie_info(title: str, year: int | None = None) -> Info | None:
     alternative_titles = sorted(alt_titles_set) if alt_titles_set else None
 
     # Extract full cast
-    credits = details.get("credits", {})
-    cast_data = credits.get("cast", [])
+    credits_data = details.get("credits", {})
+    cast_data = credits_data.get("cast", [])
     cast = [
         CastMember(
             name=c["name"],
@@ -424,7 +424,7 @@ async def fetch_movie_info(title: str, year: int | None = None) -> Info | None:
     ]
 
     # Extract director from crew
-    crew = credits.get("crew", [])
+    crew = credits_data.get("crew", [])
     directors = [c["name"] for c in crew if c.get("job") == "Director"]
     director = directors[0] if directors else None
 
@@ -512,8 +512,8 @@ async def fetch_series_info(title: str) -> Info | None:
     keywords = [k["name"] for k in keywords_data]
 
     # Extract full cast
-    credits = details.get("credits", {})
-    cast_data = credits.get("cast", [])
+    credits_data = details.get("credits", {})
+    cast_data = credits_data.get("cast", [])
     cast = [
         CastMember(
             name=c["name"],
diff --git a/mediahive/index_store.py b/mediahive/index_store.py
index fb9c99d..6494613 100644
--- a/mediahive/index_store.py
+++ b/mediahive/index_store.py
@@ -96,7 +96,7 @@ class IndexStore:
             logger.exception("Failed to load snapshot from %s", self.snapshot_path)
 
     def _load_snapshot_sync(self, raw: bytes) -> None:
-        """Synchronous snapshot parsing (runs in thread pool)."""
+        """Parse snapshot bytes in a thread-pool context."""
         data = msgspec.json.decode(raw, type=IndexSnapshot)
         for m in data.movies:
             if m.showreel_source_sets:
diff --git a/mediahive/models/data.py b/mediahive/models/data.py
index e3a8cb3..4e6536a 100644
--- a/mediahive/models/data.py
+++ b/mediahive/models/data.py
@@ -116,7 +116,8 @@ class IndexSnapshot(msgspec.Struct):
     movies: list[Movie] = []
     series: list[Series] = []
 
-    def __post_init__(self):
+    def __post_init__(self) -> None:
+        """Populate default stats when omitted from decoded payload."""
         if self.stats is msgspec.UNSET:
             self.stats = MediaStats()
 
diff --git a/mediahive/root_registry.py b/mediahive/root_registry.py
index 7a55d56..dc232f1 100644
--- a/mediahive/root_registry.py
+++ b/mediahive/root_registry.py
@@ -144,7 +144,7 @@ class RootContext:
             logger.exception("Error flushing snapshot for root %s", self.root_id)
 
     async def send_event(self, event: ScanEvent) -> None:
-        """Called by the scanner to push an event into this root's queue."""
+        """Push a scanner event into this root's queue."""
         await self._events.put(event)
 
     async def _consume_events(self) -> None:
diff --git a/mediahive/winmain.py b/mediahive/winmain.py
index 71b63a1..d49bdd2 100644
--- a/mediahive/winmain.py
+++ b/mediahive/winmain.py
@@ -578,8 +578,7 @@ def _start_gamepad_remote(
 
 
 def _setup_logging() -> Path:
-    """Redirect stdout/stderr and configure logging to a file in
-    %APPDATA%/mediahive/.
+    """Redirect stdout/stderr and configure logging to a file in %APPDATA%/mediahive/.
 
     In a PyInstaller --windowed build there is no console, so any print() or
     unhandled exception traceback would be lost.  This ensures everything ends
diff --git a/rtorrent_client.py b/rtorrent_client.py
index 4deab00..0380c29 100644
--- a/rtorrent_client.py
+++ b/rtorrent_client.py
@@ -13,7 +13,7 @@ class SCGITransport(xmlrpc.client.Transport):
         super().__init__()
         self.socket_path = socket_path
 
-    def single_request(self, host, handler, request_body, verbose=False):
+    def single_request(self, _host, _handler, request_body, _verbose=False):
         # Create SCGI request
         headers = f"CONTENT_LENGTH\x00{len(request_body)}\x00SCGI\x001\x00"
         request = f"{len(headers)}:{headers},{request_body.decode('utf-8')}"
@@ -68,6 +68,7 @@ class RTorrentClient:
 
     def load_torrent(self, torrent_path: Path, download_dir: Path) -> bool:
         """Load a torrent file and set its download directory.
+
         Uses load.start_verbose to load and immediately start/hash-check.
 
         Args:
diff --git a/scripts/devserver.py b/scripts/devserver.py
index 85c74fd..3afd2da 100644
--- a/scripts/devserver.py
+++ b/scripts/devserver.py
@@ -11,7 +11,7 @@ from pathlib import Path
 
 # Import util.py from scripts/fastapi-vue (not a package, so we adjust sys.path)
 sys.path.insert(0, str(Path(__file__).with_name("fastapi-vue")))
-from devutil import (  # type: ignore
+from devutil import (  # type: ignore[import-not-found]
     ProcessGroup,
     check_ports_free,
     logger,
diff --git a/scripts/fastapi-vue/build-frontend.py b/scripts/fastapi-vue/build-frontend.py
index 46036db..2f3d60f 100644
--- a/scripts/fastapi-vue/build-frontend.py
+++ b/scripts/fastapi-vue/build-frontend.py
@@ -3,7 +3,9 @@
 import sys
 from pathlib import Path
 
-from hatchling.builders.hooks.plugin.interface import BuildHookInterface  # type: ignore
+from hatchling.builders.hooks.plugin.interface import (  # type: ignore[import-not-found]
+    BuildHookInterface,
+)
 
 sys.path.insert(0, str(Path(__file__).parent))
 from buildutil import build
diff --git a/scripts/fastapi-vue/devutil.py b/scripts/fastapi-vue/devutil.py
index ac02bd0..c4b05b7 100644
--- a/scripts/fastapi-vue/devutil.py
+++ b/scripts/fastapi-vue/devutil.py
@@ -9,7 +9,7 @@ import sys
 from collections.abc import Coroutine
 from contextlib import suppress
 from pathlib import Path
-from typing import Any
+from typing import Any, Self
 
 import httpx
 from buildutil import find_dev_tool, find_install_tool, logger
@@ -58,10 +58,15 @@ class ProcessGroup:
             logger.warning("%s failed with exit status %d", e.cmd, e.returncode)
             raise SystemExit(1) from None
 
-    async def __aenter__(self):
+    async def __aenter__(self) -> Self:
+        """Return this process group context manager."""
         return self
 
-    async def __aexit__(self, exc_type, *_):
+    async def __aexit__(
+        self,
+        exc_type: type[BaseException] | None,
+        *_: object,
+    ) -> None:
         """Wait for one process to exit, terminate others, then wait for all."""
         await self._cleanup(immediate=exc_type is not None)
 
diff --git a/scripts/guibuild.py b/scripts/guibuild.py
index 9934157..9de9451 100644
--- a/scripts/guibuild.py
+++ b/scripts/guibuild.py
@@ -74,8 +74,8 @@ def fetch_ffmpeg() -> Path:
         ffmpeg_entry = next(
             name for name in zf.namelist() if name.endswith("/bin/ffmpeg.exe")
         )
-        with zf.open(ffmpeg_entry) as src, Path(dest).open("wb") as out:
-            out.write(src.read())
+        with zf.open(ffmpeg_entry) as src:
+            Path(dest).write_bytes(src.read())
 
     print(f"ffmpeg staged at {dest} ({dest.stat().st_size // 1024 // 1024} MB)")
     return dest
@@ -109,8 +109,8 @@ def fetch_macos_arm64_binaries() -> dict[str, Path]:
                 for name in zf.namelist()
                 if Path(name).name == tool_name and not name.endswith("/")
             )
-            with zf.open(entry_name) as src, Path(dest).open("wb") as out:
-                out.write(src.read())
+            with zf.open(entry_name) as src:
+                Path(dest).write_bytes(src.read())
 
         dest.chmod(dest.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
 
diff --git a/scripts/rtorrent-manager.py b/scripts/rtorrent-manager.py
index fafc81e..8ccb9cf 100644
--- a/scripts/rtorrent-manager.py
+++ b/scripts/rtorrent-manager.py
@@ -202,7 +202,7 @@ def format_size(size_bytes: int | None) -> str:
 
 
 def main() -> None:
-    """Main entry point for the torrent scanner."""
+    """Run the torrent scanner command-line workflow."""
     parser = argparse.ArgumentParser(
         description="Scan and manage torrent files",
         formatter_class=argparse.RawDescriptionHelpFormatter,