PHA studies workspace

The home base for a hazard study: a multi-node worksheet schedule with a cross-study recommendations register, a P&ID viewer with pinned annotations, and a bulk CSV import path to seed a study from an existing spreadsheet instead of retyping it.

• Starting a new HAZOP/What-If/FMEA/Checklist study or continuing one across multiple workshop sessions.
• Migrating an existing worksheet from a spreadsheet into DekEn (bulk CSV import) instead of hand re-entry.
• Keeping a study's discussion anchored to the actual P&ID rather than a separate notes document.

One worksheet-grid engine renders different columns per methodology from the same underlying deviation-row schema, so switching methodology doesn't mean switching tools.