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

translations/en.json

@@ -868,6 +868,60 @@
       "forecast_label": "Forecast low-stock products",
       "auto_add_label": "Auto-add to list when",
       "auto_add_suffix": "remaining in stock (0 = only when empty)"
+    },
+    "ha": {
+      "tab": "Home Assistant",
+      "title": "Home Assistant",
+      "hint": "Connect EverShelf to Home Assistant for automations, push notifications and REST sensors.",
+      "enabled": "Enable Home Assistant integration",
+      "connection_title": "Connection",
+      "url_label": "Home Assistant URL",
+      "url_placeholder": "http://192.168.1.50:8123",
+      "url_hint": "Base URL of your Home Assistant instance (e.g. http://homeassistant.local:8123).",
+      "token_label": "Long-Lived Access Token",
+      "token_hint": "Generate from HA Profile → Security → Long-Lived Access Tokens.",
+      "token_placeholder": "eyJhbGci...",
+      "token_saved": "Token saved (hidden for security)",
+      "test_btn": "Test connection",
+      "test_ok": "Connected to {version}",
+      "test_fail": "Connection failed: {error}",
+      "test_bad_token": "HA reachable but token is invalid",
+      "testing": "Testing…",
+      "error_no_url": "Please enter the Home Assistant URL first.",
+      "tts_title": "TTS on Smart Speaker",
+      "tts_hint": "Read recipe steps aloud on a Home Assistant media player.",
+      "tts_entity_label": "Media player entity ID",
+      "tts_entity_placeholder": "media_player.living_room",
+      "tts_entity_hint": "Entity ID of the HA media player. Find it in HA: Developer Tools → States.",
+      "tts_platform_label": "TTS platform",
+      "tts_platform_speak": "tts.speak (recommended)",
+      "tts_platform_notify": "notify.* (notification service)",
+      "tts_apply_btn": "Apply HA preset to TTS tab",
+      "tts_apply_hint": "Pre-fills the TTS tab with the Home Assistant URL and token.",
+      "tts_preset_applied": "HA preset applied to TTS tab.",
+      "webhook_title": "Webhook Automations",
+      "webhook_hint": "Send data to Home Assistant when pantry events occur. Create an HA automation with a Webhook trigger and paste the generated ID here.",
+      "webhook_id_label": "Webhook ID",
+      "webhook_id_placeholder": "evershelf_webhook_abc123",
+      "webhook_id_hint": "ID of the webhook created in HA. Copy from: HA → Settings → Automations → Create → Webhook Trigger.",
+      "webhook_events_label": "Notify on these events",
+      "event_expiry": "Expiring products (daily)",
+      "event_shopping": "Item added to shopping list",
+      "event_stock": "Stock level updated",
+      "expiry_days_label": "Expiry lead time (days)",
+      "expiry_days_hint": "Send the expiry alert N days before the expiry date.",
+      "webhook_help": "In HA: Settings → Automations → Create automation → Trigger: Webhook → copy the generated ID above.",
+      "notify_title": "Push Notifications",
+      "notify_hint": "Send push notifications to your phone via a Home Assistant notify service.",
+      "notify_service_label": "Notify service",
+      "notify_service_placeholder": "notify.mobile_app_my_phone",
+      "notify_service_hint": "HA notify service name (e.g. notify.mobile_app_phone). Leave empty to disable.",
+      "sensor_title": "REST Sensors",
+      "sensor_hint": "Add to configuration.yaml to create EverShelf sensors in Home Assistant.",
+      "sensor_copy_btn": "Copy YAML",
+      "sensor_copied": "YAML copied to clipboard!",
+      "save_btn": "Save HA settings",
+      "ha_hint": "If you use Home Assistant, use the Home Assistant tab to configure TTS, webhooks and sensors."
     }
   },
   "expiry": {