feat: add ExecCollectValuesWatch

[paralin]

No description provided.

[Copilot]

Pull Request Overview

This PR introduces a new function, ExecCollectValuesWatch, to asynchronously collect values from a directive and trigger callbacks on value changes.

• Implements add, remove, and dispose handlers with a broadcast mechanism.
• Adds a dedicated goroutine to execute callbacks based on changes and idle status.

Comments suppressed due to low confidence (1)

bus/multi.go:315

• [nitpick] The callback goroutine stops watching on error. Consider updating the function documentation to clearly state that an error returned by the callback terminates further monitoring.

					return // Stop on error