FIX: action return view

[merefield]

Summary

This branch fixes topic action UX after the Process Manager rename.

When a user takes a process action from a topic banner, the action now returns them to the Processes discovery view
instead of navigating back to the topic’s category and potentially landing on Latest. It also improves the
confirmation copy so the user is clearly acting on the current process item, not the process definition itself.

Changes

• Topic banner actions now route to discovery.processes after a successful transition.
• Confirmation text now refers to “this item” instead of “this process” or “this topic”.
• Target step confirmation is now rendered naturally, e.g.:
  • Are you sure you want to accept this item and move it to Review?
• Topic banner helper text now uses:
  • Target step: Review
    instead of the mechanical -> Review.
• Legacy workflow_transition small-action posts are supported at display time with a translation and icon alias, with
  a TODO to remove that compatibility later.
• add sponsorship link to repo

Tests

• Added system coverage for topic action confirmation, successful transition, and return to /processes.
• Added source-level coverage to keep the legacy workflow_transition translation/icon support intentional.