psm: implement the missing checkShort

[gadfort]

Summary

It was clear that providing short information along with open in #10955 was needed.
This implements the missing stub. This should be checked carefully as any flows that call check_power_grid will be impacted if there are false positives.

One possibility would be to make this opt-in?

Type of Change

• New feature
• Breaking change

Impact

Will now flag if the power grid is shorting to something.

Verification

• I have verified that the local build succeeds (./etc/Build.sh).
• I have run the relevant tests and they pass.
• My code follows the repository's formatting guidelines.
• I have included tests to prevent regressions.
• I have signed my commits (DCO).

[gemini-code-assist]

Code Review

This pull request implements a comprehensive short-checking mechanism in the Power Source Manager (psm) tool by introducing the IRShort class hierarchy and integrating it into IRSolver using Boost geometry R-trees. The feedback highlights several critical safety and code quality improvements, such as adding null checks for nets, instances, and marker categories to prevent potential crashes, explicitly including <fmt/format.h> and to ensure self-contained headers, and using prefix increments on Boost query iterators to optimize performance.