fix: resolve 4 bugs in PulseStack

[saurabhhhcodes]

Description

This PR fixes real bugs found in the codebase:

• Added rejection handler to Promise.all: an unhandled rejection in any input promise previously crashed silently.
• Added rejection handler to Promise.all: an unhandled rejection in any input promise previously crashed silently.
• Added Number.EPSILON to Math.round: prevents floating-point drift (e.g. 1.005 * 100 rounding to 100 instead of 101).
• Fixed default sort: .sort() coerces elements to strings, so [10, 9, 2] sorts as [10, 2, 9]; numeric comparator sorts correctly.

Type of Change

• Bug fix (non-breaking change fixing an issue)

How Has This Been Tested?

• Local manual testing

Checklist

• My code follows the style guidelines
• I have performed a self-review

Related Issue

Ref: #175