Add immich integration (#39078)

Co-authored-by: Joost Lekkerkerker <joostlek@outlook.com>

source/_integrations/immich.markdown

@@ -0,0 +1,62 @@
+---
+title: Immich
+description: Instructions on how to integrate an Immich user account into Home Assistant.
+ha_category:
+  - Multimedia
+  - Sensor
+ha_release: 2025.6
+ha_config_flow: true
+ha_iot_class: Local Polling
+ha_domain: immich
+ha_platforms:
+  - sensor
+ha_codeowners:
+  - '@mib1185'
+ha_integration_type: service
+---
+
+This integration allows adding an [Immich](https://immich.app/) user account to Home Assistant.
+
+## Prerequisites
+
+You need to [obtain the API key](https://immich.app/docs/features/command-line-interface#obtain-the-api-key) for your user account in your Immich instance.
+
+{% include integrations/config_flow.md %}
+
+{% configuration_basic %}
+URL:
+  description: "The URL of your Immich instance. (_e.g. `https://immich.example.com`_)."
+API key:
+  description: "API key of your user account to connect to your Immich instance."
+Verify SSL certificate:
+  description: "Whether to verify the SSL certificate when SSL encryption is used to connect to your Immich instance."
+{% endconfiguration_basic %}
+
+## Data fetching
+
+The integration polls data every 60 seconds.
+
+## Sensors
+
+The following {% term sensors %} are created. For some of those the API key needs to have admin rights.
+
+| Entity | Description | Default enabled |
+| --- | --- | --- |
+| **Disk size** | Overall size of the disk | ✅ |
+| **Disk available** | Free space on the disk  | ✅ |
+| **Disk used** | Used space on the disk | ❌ |
+| **Disk usage** | Usage of the disk in percentage | ❌ |
+| **Photos count** | Count of stored photos (_admin only_) | ✅ |
+| **Videos count** | Count of stored videos (_admin only_) | ✅ |
+| **Disk used by photos** | Used disk space by photos (_admin only_) | ❌ |
+| **Disk used by videos** | Used disk space by videos (_admin only_) | ❌ |
+
+## Troubleshooting
+
+In any case, when reporting an issue, please enable [debug logging](/docs/configuration/troubleshooting/#debug-logs-and-diagnostics), restart the integration, and as soon as the issue reoccurs stop the debug logging again (_download of debug log file will start automatically_).
+
+## Remove the integration
+
+{% include integrations/remove_device_service.md %}
+
+If the API key is not used anymore, you can remove it from your Immich instance.