feat: full Home Assistant integration

- PHP: _fireHaWebhook(), _sendHaNotify(), haInventorySensor(), haTestConnection()
- PHP: ha_sensor + ha_test routing actions
- PHP: getServerSettings() exposes ha_token (consistent with tts_token)
- PHP: saveSettings() handles all HA_* env keys (url, token, tts_entity, webhook_id, events, notify_service, expiry_days)
- PHP: bringAddItems(), shoppingAdd(), updateInventory() fire shopping_add / stock_update webhooks
- Cron: daily HA expiry/expired webhook + push notify with flag-file guard
- HTML: 🏠 Settings tab button + full HA panel (connection, TTS, webhook, notify, sensor cards)
- JS: serverKeys + loadSettingsUI extended with HA fields
- JS: _applyHaSettingsUI(), _loadHaTab(), _renderHaSensorYaml()
- JS: onHaEnabledChange(), testHaConnection(), applyHaTtsPreset()
- JS: saveHaSettings(), copyHaSensorYaml(), showHaWebhookHelp()
- JS: _buildHaTtsRequest() for HA media_player TTS
- JS: speakCookingStep() now supports HA TTS as first-priority path
- JS: onTtsEngineChange() fixed to show server section for both 'server' and 'custom'
- Translations: settings.ha.* (52 keys) in all 5 languages (it/en/de/fr/es)
- .env.example: HA_ENABLED/URL/TOKEN/TTS_ENTITY/WEBHOOK_ID/EVENTS/NOTIFY_SERVICE/EXPIRY_DAYS
- docs/wiki/Home-Assistant.md: new wiki page (REST sensors, webhooks, TTS, push notify, troubleshooting)
- README: HA integration highlighted as first feature block

README.md

@@ -42,6 +42,10 @@
 
 ## ✨ Features
 
+> 🏠 **New — Native Home Assistant Integration**
+> Connect EverShelf to your smart home: expose pantry counts as **REST sensors**, fire **webhook automations** on expiry/shopping/stock events, receive **push notifications** via any `notify.*` service, and read recipe steps aloud on **smart speakers** with full TTS support.
+> Configure everything from the new **Settings → 🏠** tab — no YAML editing required. See the [Home Assistant wiki page](docs/wiki/Home-Assistant.md) for details.
+
 > ⚙️ **New in v1.7.23 — Global settings tab, DB auto-cleanup, vacuum-sealed expiry**
 > A new **General** tab groups all global settings (language, currency, theme, screensaver, zero-waste, export) in one place.
 > Recipes older than `RECIPE_RETENTION_DAYS` and transactions older than `TRANSACTION_RETENTION_DAYS` are deleted automatically every cron cycle, followed by a SQLite `VACUUM` to keep the database small.