Signal action: let the operator choose which branch to follow

The process instance page offers a Signal action on a parked token, but it resumes the token with no outcome. A wait node's conditional outgoing flows then do not match the branch the operator intended, so the token falls through to the default arc, often straight to completion. For a wait node with real branches (for example paid / cancelled / back) a no-outcome signal is almost never what the operator wants.

Proposed change

Replace the one-click signal with a small form that lists the parked node's outgoing branches and lets the operator pick one.

• The branches are read from the node's outgoing flows: each flow with a comparison condition becomes a choice, labelled with the flow label.
• Choosing a branch signals the token with that condition's variable set to its value, so the chosen flow matches and the token follows it.
• An "Advance with no outcome" choice is kept for a node whose default arc is unconditional, preserving today's behaviour.

Scope

orchestra_ui only: the signal route becomes a form, reading the outgoing flows via the workflow definition and resuming through the existing engine signal(). No engine change.