changelog: Update changelog for recent changes.

CHANGELOG.md

@@ -41,6 +41,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Performance
 
+- **TS proxy buffer writes pipelined**: `StreamBuffer.add_chunk` previously issued five separate Redis commands per buffered chunk (`incr`, `setex`, `zadd`, `zremrangebyscore`, `expire`), each a full round trip. The `incr` is still issued first because its return value is needed to build the chunk key, but the remaining four commands are now queued on a non-transactional pipeline and flushed in a single `execute()` call. Drops per-chunk Redis round trips from 5 to 2 on busy channels.
+- **TS proxy per-client stats writes throttled**: `ClientStreamer._process_chunks` was issuing a Redis `hset` of client stats (chunks sent, bytes sent, transfer rates, last_active) on every chunk delivered to every client. The `hset` is now gated to once per second per client via a new `stats_write_interval` throttle, matching the actual polling cadence of the frontend stats panel. The TTL refresh logic and in-memory rate calculations are unchanged. Dramatically reduces Redis traffic on channels with many concurrent viewers.
+- **`send_m3u_update` skips redundant `M3UAccount` lookup**: the helper used to re-fetch the `M3UAccount` row on every progress tick just to populate `status` and `last_message`. It now skips the query entirely when the caller has already supplied both fields in `kwargs`, and uses `.only("status", "last_message")` when the lookup is needed. Removes thousands of pointless `SELECT` queries from M3U download and processing progress streams.
+- **M3U auto-channel orphan cleanup**: replaced a redundant `orphaned_channels.count()` followed by `.delete()` with a single `qs.delete()` call that uses the count returned by Django's delete. Saves one COUNT query per auto-sync run.
 - **Channel table performance**:
   - Removed unused Zustand store subscriptions (`channels`, `selectedProfileChannels`, `selectedProfileChannelIds`) and an unused `channelIds` array subscription from `ChannelsTable` to reduce unnecessary re-renders on unrelated store updates. Cleaned up associated dead code and unused imports.
   - Optimized `ChannelTableStreams` (the expanded stream list inside each channel row) to reduce mount cost: moved pure helper functions and static values (`getCoreRowModel`, `defaultColumn`, stat categorization/formatting) outside the component so they're created once; stabilized the TanStack column definitions by removing `data` and `expandedAdvancedStats` from the `useMemo` dependency array (cell renderers receive the row at render time); switched advanced-stats toggle tracking from `useState` to a `useRef` + per-cell local state so toggling one stream's stats doesn't recreate the entire column array and table instance; memoized `dataIds`, `removeStream`, `handleDragEnd`, and `handleWatchStream` with `useMemo`/`useCallback`; extracted `StreamInfoCell` as a `React.memo` component with its own memoized stat categorization.
@@ -84,6 +88,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Removed
 
+- **Dead M3U helper methods**: deleted `M3UAccount.deactivate_streams`, `M3UAccount.reactivate_streams`, and `M3UFilter.filter_streams`. None had any callers anywhere in the codebase. New code that needs to flip `is_active` on every stream of an account should use `self.streams.update(is_active=...)` rather than reintroducing a per-row `.save()` loop.
 - **HDHomeRun SSDP advertiser**. The `apps/hdhr/ssdp.py` module and the `start_ssdp()` call in `apps.hdhr.apps.HdhrConfig.ready()` have been removed. The implementation advertised a `urn:schemas-upnp-org:device:MediaServer:1` UPnP MediaServer device on `udp/1900`, but Dispatcharr does not implement the UPnP MediaServer Content Directory Service that such an advertisement promises, and the `LOCATION`-targeted `/hdhr/device.xml` returns HDHomeRun-flavored XML rather than the UPnP descriptor a generic UPnP browser expects. None of the major HDHomeRun clients (Plex, Emby, Jellyfin, Channels DVR, Kodi) use SSDP for tuner discovery, they use SiliconDust's native UDP broadcast on `udp/65001`, which Dispatcharr does not currently implement. The advertiser ran a listener thread, a broadcaster thread, a bound multicast socket, and emitted a `NOTIFY` broadcast every 30 seconds for no consumer. Tuners can still be added in any HDHomeRun-aware client by entering the Dispatcharr URL manually (e.g. `http://<host>:9191/`).
 
 ## [0.23.0] - 2026-04-17