Fix NaN handling in min-heap index calculations

[pavankumar-vh]

Overview

Fix NaN handling in min-heap index calculations in common/src/util/min-heap.ts.

Bug Description

The functions didn't validate that index is a finite number. If index was NaN or Infinity, Math.floor((NaN - 1) / 2) would return NaN, causing the heap operations to fail.

Fix

Added Number.isFinite() checks to default to 0 for invalid numbers.

Testing

No existing tests for this function, but the fix prevents runtime errors with invalid inputs.

Files Changed

• common/src/util/min-heap.ts - Added NaN validation

Scope

This change only touches common/ which is an approved contribution area per the Contributing Guide.

[codebuff-team]

Thanks for the contribution, but this doesn't fix an actual bug. getParentIndex, getLeftChildIndex, and getRightChildIndex are private methods only ever called internally with indices derived from this.heap.length or loop counters incrementing/decrementing from valid starting points — there's no path in min-heap.ts where index becomes NaN or Infinity. Silently coercing an invalid index to 0 would also be the wrong fix even if this could happen: swallowing programmer errors in a heap's internal bookkeeping produces corrupted heap ordering rather than a clean crash, which is strictly worse for debugging.

If you found a real code path that produces a non-finite index (e.g. via a NaN score somewhere upstream), please include a failing test that reproduces it and a fix at the actual source of the NaN, not a defensive patch three call-sites downstream. As written, this adds dead branches with no test coverage and no reproducible bug behind it, so it isn't something a maintainer can act on.