Update HA docs with MQTT example (#22098)

* update HA docs with MQTT example

* format block as yaml

docs/docs/configuration/snapshots.md

@@ -9,4 +9,25 @@ Snapshots are accessible in the UI in the Explore pane. This allows for quick su
 
 To only save snapshots for objects that enter a specific zone, [see the zone docs](./zones.md#restricting-snapshots-to-specific-zones)
 
-Snapshots sent via MQTT are configured in the [config file](https://docs.frigate.video/configuration/) under `cameras -> your_camera -> mqtt`
+Snapshots sent via MQTT are configured in the [config file](/configuration) under `cameras -> your_camera -> mqtt`
+
+## Frame Selection
+
+Frigate does not save every frame — it picks a single "best" frame for each tracked object and uses it for both the snapshot and clean copy. As the object is tracked across frames, Frigate continuously evaluates whether the current frame is better than the previous best based on detection confidence, object size, and the presence of key attributes like faces or license plates. Frames where the object touches the edge of the frame are deprioritized. The snapshot is written to disk once tracking ends using whichever frame was determined to be the best.
+
+MQTT snapshots are published more frequently — each time a better thumbnail frame is found during tracking, or when the current best image is older than `best_image_timeout` (default: 60s). These use their own annotation settings configured under `cameras -> your_camera -> mqtt`.
+
+## Clean Copy
+
+Frigate can produce up to two snapshot files per event, each used in different places:
+
+| Version | File | Annotations | Used by |
+| --- | --- | --- | --- |
+| **Regular snapshot** | `<camera>-<id>.jpg` | Respects your `timestamp`, `bounding_box`, `crop`, and `height` settings | API (`/api/events/<id>/snapshot.jpg`), MQTT (`<camera>/<label>/snapshot`), Explore pane in the UI |
+| **Clean copy** | `<camera>-<id>-clean.webp` | Always unannotated — no bounding box, no timestamp, no crop, full resolution | API (`/api/events/<id>/snapshot-clean.webp`), [Frigate+](/plus/first_model) submissions, "Download Clean Snapshot" in the UI |
+
+MQTT snapshots are configured separately under `cameras -> your_camera -> mqtt` and are unrelated to the clean copy.
+
+The clean copy is required for submitting events to [Frigate+](/plus/first_model) — if you plan to use Frigate+, keep `clean_copy` enabled regardless of your other snapshot settings.
+
+If you are not using Frigate+ and `timestamp`, `bounding_box`, and `crop` are all disabled, the regular snapshot is already effectively clean, so `clean_copy` provides no benefit and only uses additional disk space. You can safely set `clean_copy: False` in this case.

docs/docs/integrations/home-assistant.md

@@ -16,7 +16,15 @@ See the [MQTT integration
 documentation](https://www.home-assistant.io/integrations/mqtt/) for more
 details.
 
-In addition, MQTT must be enabled in your Frigate configuration file and Frigate must be connected to the same MQTT server as Home Assistant for many of the entities created by the integration to function.
+In addition, MQTT must be enabled in your Frigate configuration file and Frigate must be connected to the same MQTT server as Home Assistant for many of the entities created by the integration to function, e.g.:
+
+```yaml
+mqtt:
+  enabled: True
+  host: mqtt.server.com # the address of your HA server that's running the MQTT integration
+  user: your_mqtt_broker_username
+  password: your_mqtt_broker_password
+```
 
 ### Integration installation
 
@@ -95,12 +103,12 @@ services:
 
 If you are using Home Assistant Add-on, the URL should be one of the following depending on which Add-on variant you are using. Note that if you are using the Proxy Add-on, you should NOT point the integration at the proxy URL. Just enter the same URL used to access Frigate directly from your network.
 
-| Add-on Variant             | URL                                       |
-| -------------------------- | ----------------------------------------- |
-| Frigate                    | `http://ccab4aaf-frigate:5000`            |
-| Frigate (Full Access)      | `http://ccab4aaf-frigate-fa:5000`         |
-| Frigate Beta               | `http://ccab4aaf-frigate-beta:5000`       |
-| Frigate Beta (Full Access) | `http://ccab4aaf-frigate-fa-beta:5000`    |
+| Add-on Variant             | URL                                    |
+| -------------------------- | -------------------------------------- |
+| Frigate                    | `http://ccab4aaf-frigate:5000`         |
+| Frigate (Full Access)      | `http://ccab4aaf-frigate-fa:5000`      |
+| Frigate Beta               | `http://ccab4aaf-frigate-beta:5000`    |
+| Frigate Beta (Full Access) | `http://ccab4aaf-frigate-fa-beta:5000` |
 
 ### Frigate running on a separate machine
 

docs/docs/integrations/mqtt.md

@@ -120,7 +120,7 @@ Message published for each changed tracked object. The first message is publishe
 
 ### `frigate/tracked_object_update`
 
-Message published for updates to tracked object metadata, for example:
+Message published for updates to tracked object metadata. All messages include an `id` field which is the tracked object's event ID, and can be used to look up the event via the API or match it to items in the UI.
 
 #### Generative AI Description Update
 
@@ -134,12 +134,14 @@ Message published for updates to tracked object metadata, for example:
 
 #### Face Recognition Update
 
+Published after each recognition attempt, regardless of whether the score meets `recognition_threshold`. See the [Face Recognition](/configuration/face_recognition) documentation for details on how scoring works.
+
 ```json
 {
   "type": "face",
   "id": "1607123955.475377-mxklsc",
-  "name": "John",
-  "score": 0.95,
+  "name": "John", // best matching person, or null if no match
+  "score": 0.95, // running weighted average across all recognition attempts
   "camera": "front_door_cam",
   "timestamp": 1607123958.748393
 }
@@ -147,11 +149,13 @@ Message published for updates to tracked object metadata, for example:
 
 #### License Plate Recognition Update
 
+Published when a license plate is recognized on a car object. See the [License Plate Recognition](/configuration/license_plate_recognition) documentation for details.
+
 ```json
 {
   "type": "lpr",
   "id": "1607123955.475377-mxklsc",
-  "name": "John's Car",
+  "name": "John's Car", // known name for the plate, or null
   "plate": "123ABC",
   "score": 0.95,
   "camera": "driveway_cam",