added server tracking plus server metrics

db_async.py

@@ -126,6 +126,41 @@ character_inventories = Table(
     UniqueConstraint("character_name", "item_id", name="uq_char_item"),
 )
 
+# Server health monitoring tables
+server_health_checks = Table(
+    # Time-series data for server health checks
+    "server_health_checks",
+    metadata,
+    Column("id", Integer, primary_key=True),
+    Column("server_name", String, nullable=False, index=True),
+    Column("server_address", String, nullable=False),
+    Column("timestamp", DateTime(timezone=True), nullable=False, default=sqlalchemy.func.now()),
+    Column("status", String(10), nullable=False),  # 'up' or 'down'
+    Column("latency_ms", Float, nullable=True),
+    Column("player_count", Integer, nullable=True),
+)
+
+server_status = Table(
+    # Current server status and uptime tracking
+    "server_status",
+    metadata,
+    Column("server_name", String, primary_key=True),
+    Column("current_status", String(10), nullable=False),
+    Column("last_seen_up", DateTime(timezone=True), nullable=True),
+    Column("last_restart", DateTime(timezone=True), nullable=True),
+    Column("total_uptime_seconds", BigInteger, default=0),
+    Column("last_check", DateTime(timezone=True), nullable=True),
+    Column("last_latency_ms", Float, nullable=True),
+    Column("last_player_count", Integer, nullable=True),
+)
+
+# Index for efficient server health check queries
+Index(
+    'ix_server_health_checks_name_ts',
+    server_health_checks.c.server_name,
+    server_health_checks.c.timestamp.desc()
+)
+
 async def init_db_async():
     """Initialize PostgreSQL/TimescaleDB schema and hypertable.