Add dynamic configuration for more fields (#22295)

* face recognition dynamic config

* lpr dynamic config

* safe changes for birdseye dynamic config

* bird classification dynamic config

* always assign new config to stats emitter to make telemetry fields dynamic

* add wildcard support for camera config updates in config_set

* update restart required fields for global sections

* add test

* fix rebase issue

* collapsible settings sidebar

use the preexisting control available with shadcn's sidebar (cmd/ctrl-B) to give users more space to set masks/zones on smaller screens

* dynamic ffmpeg

* ensure previews dir exists

when ffmpeg processes restart, there's a brief window where the preview frame generation pipeline is torn down and restarted. before these changes, ffmpeg only restarted on crash/stall recovery or full Frigate restart. Now that ffmpeg restarts happen on-demand via config changes, there's a higher chance a frontend request hits the preview_mp4 or preview_gif endpoints during that brief restart window when the directory might not exist yet. The existing os.listdir() call would throw FileNotFoundError without a directory existence check. this fix just checks if the directory exists and returns 404 if not, exactly how preview_thumbnail already handles the same scenario a few lines below

* global ffmpeg section

* clean up

* tweak

* fix test

frigate/output/output.py

@@ -15,6 +15,7 @@ from ws4py.server.wsgirefserver import (
 )
 from ws4py.server.wsgiutils import WebSocketWSGIApplication
 
+from frigate.comms.config_updater import ConfigSubscriber
 from frigate.comms.detections_updater import DetectionSubscriber, DetectionTypeEnum
 from frigate.comms.ws import WebSocket
 from frigate.config import FrigateConfig
@@ -138,6 +139,7 @@ class OutputProcess(FrigateProcess):
                 CameraConfigUpdateEnum.record,
             ],
         )
+        birdseye_config_subscriber = ConfigSubscriber("config/birdseye", exact=True)
 
         jsmpeg_cameras: dict[str, JsmpegCamera] = {}
         birdseye: Birdseye | None = None
@@ -167,6 +169,20 @@ class OutputProcess(FrigateProcess):
         websocket_thread.start()
 
         while not self.stop_event.is_set():
+            update_topic, birdseye_config = (
+                birdseye_config_subscriber.check_for_update()
+            )
+
+            if update_topic is not None:
+                previous_global_mode = self.config.birdseye.mode
+                self.config.birdseye = birdseye_config
+
+                for camera_config in self.config.cameras.values():
+                    if camera_config.birdseye.mode == previous_global_mode:
+                        camera_config.birdseye.mode = birdseye_config.mode
+
+                logger.debug("Applied dynamic birdseye config update")
+
             # check if there is an updated config
             updates = config_subscriber.check_for_updates()
 
@@ -297,6 +313,7 @@ class OutputProcess(FrigateProcess):
             birdseye.stop()
 
         config_subscriber.stop()
+        birdseye_config_subscriber.stop()
         websocket_server.manager.close_all()
         websocket_server.manager.stop()
         websocket_server.manager.join()