superguardado: fixes pi_bot (offset persistente, unit systemd) + voz.py (desconectar chromecast) + lecciones 27-31

vigilancia/pi_bot.py

@@ -9,6 +9,7 @@ import requests
 
 BASE = os.path.dirname(os.path.abspath(__file__))
 LOG = os.path.join(BASE, "bot.log")
+OFFSET_FILE = os.path.join(BASE, "bot.offset")
 TV_API = "http://127.0.0.1:8600/tv/mensaje"
 
 
@@ -174,13 +175,29 @@ def monitor_temperatura():
                    f"(límite {ALERTA_TEMP}°C)\n{msg}", CHAT_ID)
 
 
+def cargar_offset():
+    try:
+        with open(OFFSET_FILE) as f:
+            return int(f.read().strip())
+    except Exception:
+        return None
+
+
+def guardar_offset(offset):
+    try:
+        with open(OFFSET_FILE, "w") as f:
+            f.write(str(offset))
+    except Exception:
+        pass
+
+
 def main():
     if not TOKEN:
         print("Falta TELEGRAM_TOKEN en .env")
         return
     threading.Thread(target=monitor_temperatura, daemon=True).start()
-    offset = None
-    log("Bot iniciado")
+    offset = cargar_offset()
+    log("Bot iniciado" + (f" (offset {offset})" if offset else ""))
     print("Bot iniciado. Esperando mensajes...")
     while True:
         try:
@@ -193,6 +210,7 @@ def main():
             ).json()
             for upd in r.get("result", []):
                 offset = upd["update_id"] + 1
+                guardar_offset(offset)
                 log(f"UPDATE {upd.get('update_id')}")
                 msg = upd.get("message") or upd.get("channel_post")
                 if not msg: