Issue #3611508: Sync the API spec, docs and translations with the state rename and the new instance fields

Syncs the API spec, docs and translations with the shipped state rename (#3611318) and the newer instance fields.

• D1: docs/openapi.yaml renames the status query parameter and the status schema properties to state, and adds definition_version, status, initiator and correlation_key to the instance schemas.
• G4: the client DTO (OrchestraClientInterface, LocalOrchestraClient) now exposes status, initiator, correlation_key and definition_version on getInstance(), and status + initiator on the listInstances() summaries.
• D2: architecture, incidents, troubleshooting, retention, roadmap and versioning docs now call the engine lifecycle "state", not "status".
• D3: the roadmap Built inventory lists the shipped requester surface (initiator, My requests, the status vocabulary, the detail view).
• D4: the ~50 WorkItem/assignment/timeout strings the #3610809 code move stranded are moved from the orchestra_inbox po to the base po (with their existing French), the dead inbox entries pruned, and the new status-vocabulary CRUD strings added to orchestra_ui.
• D5: the banned arrow glyph in the Complete Modeler form title is replaced.

A LocalOrchestraClient kernel test now pins the extended DTO. Note: a smaller set of orchestra_interaction message-stacking strings remains to translate in a follow-up.