Issue #3611212: Requester-facing list of a user's own process instances (a "my requests" page and a "my workflow instances" View)

Adds the requester-facing side of the process initiator: a themed My requests page (orchestra_ui, /orchestra/my-requests) and an example My workflow instances View (orchestra_views, /orchestra/my-instances), both scoped to the current user's initiator and the acting tenant and gated by a new View own process instances permission.

Backed by a reusable orchestra.current_step_resolver service and a Current step Views field. The View is a clonable example living in the dedicated Views submodule. A read-only view-detail link is intentionally left out of this MVP (per-request detail is source-specific).

Kernel tests cover the resolver, the page and the View; docs and French translations included.

Fixes #3611212.