Initial release: Matrix Messenger Home Assistant integration

- Config flow (GUI): Homeserver, Passwort- oder Token-Anmeldung, Raumauswahl
- E2EE-Unterstützung via matrix-nio mit SQLite Key-Store
- Aktionen: send_message, ask_question (Text + Emoji-Reaktion)
- notify.*-Entitäten pro Raum
- Optionaler Hintergrund-Sync, 30-Min-Timeout für Fragen
- HACS-kompatibel, HA >= 2026.4.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

custom_components/matrix_messenger/manifest.json

@@ -0,0 +1,12 @@
+{
+  "domain": "matrix_messenger",
+  "name": "Matrix Messenger",
+  "codeowners": [],
+  "config_flow": true,
+  "documentation": "",
+  "homeassistant": "2026.4.0",
+  "iot_class": "cloud_push",
+  "requirements": ["matrix-nio[e2e]>=0.21.0"],
+  "version": "1.0.0",
+  "integration_type": "hub"
+}