feat(app): expand region analysis and figure annotations

[nmrtist]

Summary

• Generalize region analysis into a persisted, capability-driven workflow shared by pseudo-2D series and electrophysiology recordings. Regions use stable owner-scoped IDs, per-region metrics, labels, colors, and source-field provenance; linked series tables stay synchronized with region, sweep, channel, and processing edits.
• Turn regions into figure content rather than editor-only chrome. Screen, SVG, EMF, PDF, bitmap, and vector clipboard rendering preserve colored bands, boundaries, and labels, while selection handles and drag previews remain editor-only.
• Add direct manipulation and styling for figure furniture. Legends and region labels can be dragged and reset with a double-click; legend visibility, position, size, and text color are persisted and undoable. Semantic series colors and combined point/fit legend entries remain consistent across source figures, linked tables, fits, and exports.
• Use selected regions as electrophysiology statistics and IV windows, reject non-finite analysis samples instead of filtering across gaps, and keep region selection scoped to its source dataset.
• Update project persistence, export prechecks, property discovery, automation capabilities, tests, and the English/Simplified Chinese guides for the complete workflow.

The project format remains v1. PlotX has not had a public v1 project release, so this intentionally treats the current schema as the first v1 contract and does not migrate development-only draft formats.

Validation

• cargo pr-check
• npm run build in docs/ (71 pages)
• git diff --check
• Focused regression tests for owner-scoped region selection, electrophysiology non-finite windows, default-metric dirty state and linked-table synchronization, and Browse Zoom box previews

UI display logic

• New or changed actions go through the command catalog (CommandId + describe) and are searchable in the command palette.
• Hiding happens only at Ribbon-group level (dataset kind or width budget); transient states disable with a disabled_reason that says how to unblock.
• No layout changes from background events; panels are never auto-closed.
• New panels or empty regions show an empty state with a next step.
• Docs updated in docs/ (English and zh-CN) for user-visible behavior.