feat: create save new agent in db

internal/hub/store/sqlc/queries/agent.sql

@@ -1,3 +1,16 @@
 -- name: CreateAgent :exec
 INSERT INTO agents (agent_id, agent_name, architecture, system, hostname, version, capabilities)
-VALUES  ($1, $2, $3, $4, $5, $6, $7);
+VALUES  ($1, $2, $3, $4, $5, $6, $7);
+
+-- name: GetAgentByID :one
+SELECT * from agents
+WHERE id=$1;
+
+-- name: GetAgentByAgentID :one
+SELECT * from agents
+WHERE agent_id=$1;
+
+-- name: UpdateAgentByID :exec
+UPDATE agents
+SET agent_id=$1, agent_name=$2, architecture=$3, system=$4, hostname=$5, version=$6, capabilities=$7
+WHERE id=$8;