Compute Maximum Area Under Adjacent Bars

You are given an array `heights` of `n` non-negative integers. Each value represents the height of a vertical bar of width `1`, and the bars are placed next to each other. Choose any contiguous range of bars. Within that range, you may form a rectangle whose height is at most the minimum bar height in the range and whose width is the number of bars in the range. Return the maximum possible rectangle area. Constraints: - `1 <= n <= 100000` - `0 <= heights[i] <= 1000000000` - The answer may require 64-bit integer arithmetic. Example: - Input: `heights = [2, 1, 5, 6, 2, 3]` - Output: `10` - Explanation: Choosing the bars with heights `5` and `6` gives height `5`, width `2`, and area `10`.