[translator] Epic: editor-facing translation workflow

## Goal

The plugin covers the **core translation engine** — deep translation of localized fields (groups/arrays/blocks/tabs), Lexical rich text, bulk + per-document flows, pluggable provider and runner. This epic tracks the **editor-facing workflow layer** on top of it, plus the primitives that unlock it.

## Foundation (keystone)

- [ ] #47 — Record translation provenance + lifecycle events

Most features below need to reason about *what a translation was derived from* or *react when one happens*. #47 adds per-locale provenance + lifecycle callbacks and unblocks the rest.

## Workflow features

Standalone (no dependency on the foundation):

- [ ] #46 — Configurable single/multi target-language selection
- [ ] #48 — Per-field (selective) translation within a run
- [ ] #49 — Global cross-collection translation dashboard

Build on the foundation:

- [ ] #50 — Detect & surface out-of-sync (stale) translations *(depends on #47)*
- [ ] #51 — Auto-translate on source content change *(depends on #47, benefits from #50)*

## Suggested order

1. #47 (foundation) — unblocks #50 and #51.
2. #46, #48, #49 — independent; can land any time.
3. #50 — once #47 lands.
4. #51 — once #47 (and ideally #50) land.

## Out of scope

Grouping translation **variants into editorial sets** (and tying that to a market/region model) is consumer-specific — it belongs in the consuming app and would build on the per-locale status + staleness primitives (#47, #50) rather than in the plugin.

The issue names no files, tests, or entry points. Start by reviewing the referenced issues #47–#51 and their dependencies, then use their acceptance details to define the editor-facing workflow scope; done means the selected workflow features are implemented and their listed dependencies are resolved.

Written by the indexing model from the issue text.