The financial stability of hundreds of Seattle tenants is on the line as public and private players vie for nearly two dozen apartment buildings that have been on the market since this summer. The entire portfolio of finished aPodment-branded micro-apartment buildings is for sale, a total of 23 properties and 1,402 apartments from Northgate to the Central District. Built by Calhoun Properties, the apartments average 177 square feet and rent for an average of $921, including internet and utilities, according to the brokers listing the buildings. Typical studio and one-bedroom apartments in Seat…