Workflow Step Assignment at PBS Edition

Feature Request: Edit workflow step assignments during PBS editing

Summary:
Enable authorized users to add, remove, or change workflow step assignees directly within the PBS edit dialog. This extends the workflow assignment capability introduced at PBS creation so teams can maintain ownership throughout the life of a PBS without requiring separate RAM View access.

Problem Statement:
Currently, workflow step assignments can be defined during PBS creation but cannot be updated during PBS editing. Once a PBS is created, any ownership changes, incorrect initial assignments, or team reorganizations must be managed through RAM View, which requires RAM admin access. This creates unnecessary dependency on administrators, slows down routine maintenance, and prevents authorized PBS users from keeping workflow ownership accurate as project responsibilities evolve.

Proposed Solution:
Replace the current read-only workflow information shown during PBS editing with an editable workflow step assignment interface that mirrors the experience available at PBS creation.
Allow authorized users to add, remove, or update assignees for any workflow step shown in the PBS edit dialog.
Apply the same RAM-derived user-pool cascade rules used at creation time, where the root PBS draws from distinct users across all RAM groups and child PBS levels draw from users assigned at the parent PBS workflow steps.
Persist assignment updates through the standard PBS update flow and generate activity feed entries for each change, including the user, target, change, and timestamp.
Respect existing lock and finalization rules so locked or finalized PBSs follow the same editing restrictions as other PBS changes.
Do not render the workflow section during PBS editing when no RAM data exists for the proposal.
Confirm the correct permission gate during spec review to determine whether PBS Edit permission, PBS Create permission, or both are required.

Benefits:
Reduces reliance on RAM administrators for routine workflow ownership changes.
Improves accuracy of workflow assignments as teams and responsibilities change over time.
Keeps PBS workflow management consistent between creation and editing experiences.
Preserves governance through existing permission, lock, and finalization controls.
Maintains traceability by recording assignment changes in the activity feed.
Improves operational efficiency by allowing authorized users to manage workflow ownership directly where they already edit PBS details.