Host hash evaluation for sync triggers requires stable metadata payload

The existing host logic computes and compares a hash of the metadata payload to identify trigger changes and ensure the platform has updated trigger information, this has worked well with static files, but with workers indexing and generating this metadata dynamically, if they are not consistent about the payload they provide, that would trigger a false positive and lead to issues where the host would continuously trigger updates and restart.

Opening this to evaluate options to make this process safer for workers and ensure that we don't trigger this process even if the payload hash is different, but semantically equivalent.

No files, tests, or entry points are named. Start by tracing the existing host hash comparison for metadata payloads and the sync-trigger update and restart path. Define how workers' semantically equivalent payloads should be recognized, and consider the work done only when the safer behavior and its validation are specified.

Written by the indexing model from the issue text.