Smoother daemon: no-op reloads, batched placement, muted audio, graceful teardown

- Skip stream restarts when a reload resolves to the identical wall
  (same URLs, tile geometry, player settings) — saving an unrelated
  config edit no longer blanks the screen.
- Replace per-tile placement polling (a swaymsg fork per tile per second,
  plus 150ms get_tree polling per tile at startup) with one shared loop:
  a single get_tree snapshot per tick, re-placing only drifted windows,
  relaxing to a 2s tick once settled.
- Mute streams by default (--no-audio) to skip an audio decoder per
  stream; opt back in with player.audio: true.
- Graceful, parallel mpv teardown via cmd.Cancel/WaitDelay, fixing the
  double-Wait race between Stop and Supervise and cutting worst-case
  layout switches from ~2s x N streams to ~2s total.
- status: probe mpv IPC outside the daemon mutex so a slow probe can't
  block layout switches.
- View sync: reuse the Protect session across ticks (re-login only on
  expiry) and pick up view_refresh_seconds changes without a restart.
- Health strikes keyed by player, not slot, so they never carry across
  layout switches; prune stale entries.
- New `rtsp-streamer reload` CLI; fix dead sort in `layout ls`; back off
  on persistent control-socket accept errors; fsync config before the
  atomic rename (SD-card power-cut safety); bump IPC client deadline;
  gofmt stragglers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -143,9 +143,15 @@ rtsp-streamer daemon             # normally launched by sway, not by hand
 rtsp-streamer status             # slot health from the running daemon
 rtsp-streamer layout ls          # list layouts (* marks active)
 rtsp-streamer layout set quad    # switch live (persists the choice)
+rtsp-streamer reload             # apply hand-edits to the config live
 rtsp-streamer version            # baked-in git commit / build date
 ```
 
+Reloads (and TUI saves) are minimal-impact: the daemon compares the resolved
+wall — stream URLs, tile geometry, player settings — against what's already
+running and leaves the streams untouched when nothing material changed, so
+saving an unrelated edit never blanks the screen.
+
 ## UniFi Protect live views
 
 Copy a saved Protect "Live View" (its cameras and grid) straight into a layout:
@@ -251,6 +257,8 @@ pegged, work through:
 - **Latency drift** is handled by `--framedrop=decoder+vo` + low-delay demuxer
   flags (built in), so a briefly-behind stream drops frames to catch up instead
   of accumulating a backlog. Capping `player.max_fps` trims render load too.
+- **Audio is off by default** (`--no-audio`), which skips one audio decoder per
+  stream. Set `player.audio: true` if you actually want camera sound.
 
 ## Troubleshooting
 
@@ -293,13 +301,12 @@ pegged, work through:
 - Layout rotation / cycling on a timer (the daemon already re-tiles on demand).
 - TUI create / delete / rename layouts (today the TUI only *edits* existing
   ones; new layouts are added in YAML).
-- `rtsp-streamer reload` CLI (so hand-edits apply live without the TUI or a
-  restart); optional git tags so `version` shows a release rather than a hash.
+- Optional git tags so `version` shows a release rather than a hash.
 
 ## Layout
 
 ```
-cmd/rtsp-streamer/   CLI (cobra): daemon, discover, layout, status, tui, config, version
+cmd/rtsp-streamer/   CLI (cobra): daemon, discover, layout, reload, status, tui, config, version
 internal/config/     YAML load/save/validate, schema (tiles, streams), XDG paths
 internal/protect/    UniFi Protect client (login, bootstrap, enable RTSP, URLs)
 internal/player/     one supervised mpv per stream, JSON IPC, restart/backoff