Pool sensor v2: VCC monitoring, database resilience, receiver improvements

- Added voltage monitoring table and storage pipeline
- Extended pool payload to 17 bytes with VCC field (protocol v2)
- Improved database connection pool resilience (reduced pool size, aggressive recycling, pool disposal on failure)
- Added environment variable support for database configuration
- Fixed receiver MQTT deprecation warning (CallbackAPIVersion.VERSION2)
- Silenced excessive RSSI status logging in receiver
- Added reset flag tracking and reporting
- Updated Docker compose with DB config and log rotation limits

data_tables.py

@@ -85,4 +85,13 @@ class Precipitation(Base):
     sensor_id = Column(Integer, ForeignKey('sensors.id'))
     sensor = relationship('Sensor', backref='precipitation')
     timestamp = Column(DateTime, default=datetime.utcnow)
-    precipitation = Column(Float)
+    precipitation = Column(Float)
+
+# Define the Voltage table
+class Voltage(Base):
+    __tablename__ = 'voltage'
+    id = Column(Integer, primary_key=True)
+    sensor_id = Column(Integer, ForeignKey('sensors.id'))
+    sensor = relationship('Sensor', backref='voltage')
+    timestamp = Column(DateTime, default=datetime.utcnow)
+    vcc_mv = Column(Integer)