feat(infra): add CasaOS compose with persistent /DATA bind

CasaOS copies imported compose files to /tmp/casaos-compose-app-* and
runs them from there, so the repo compose's relative ./data bind fails
at install ("bind source path does not exist") and would be wiped on
reboot. infra/compose.casaos.yaml mounts /DATA/AppData/dash instead and
carries x-casaos metadata for the app tile.

Authored By: TDvorak <[email protected]>

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -6,6 +6,13 @@ All notable changes to Dash. Format follows
 
 ## [Unreleased]
 
+### Added
+
+- CasaOS deployment file `infra/compose.casaos.yaml` with app-store
+  (`x-casaos`) metadata and a persistent `/DATA/AppData/dash` bind mount;
+  the repo compose's relative `./data` fails under CasaOS, which runs
+  compose from `/tmp` and loses it on reboot
+
 ## [2.1.0] — 2026-09-23
 
 ### Added