---
phase: 16-multi-signer-ui
plan: "03"
subsystem: ui
tags: [react, typescript, fieldplacer, signer-coloring, active-signer]

# Dependency graph
requires:
  - phase: 16-multi-signer-ui
    plan: "01"
    provides: signers prop + unassignedFieldIds prop threaded into FieldPlacer
provides:
  - activeSignerEmail state in FieldPlacer — auto-defaults to signers[0].email
  - Active signer selector UI (select dropdown with colored dot, shown when signers.length > 0)
  - Per-signer field coloring — dragged fields get signerEmail; color overrides type color when assigned
  - Unassigned field red highlight — border/background #ef4444 when field.id in unassignedFieldIds
  - DragOverlay ghost uses activeSigner.color

affects: [16-04-dashboard-badge]

---

# Phase 16 Plan 03: FieldPlacer Active Signer Selector and Color Override Summary

## What Was Built

Added multi-signer UX to `FieldPlacer.tsx` (822 → 907 lines):

1. **`activeSignerEmail` state** — `useState<string | null>(null)` initialized via `useEffect` to `signers[0].email` on mount; resets if signers prop changes or selected signer removed.

2. **`handleDragEnd` signer auto-assignment** — `...(activeSignerEmail ? { signerEmail: activeSignerEmail } : {})` added to `newField` construction so dragged fields are tagged automatically.

3. **`renderFields` signer color override** — `signers.find(s => s.email === field.signerEmail)?.color` overrides type-based color when the field has a signerEmail. Fields without signerEmail retain existing PALETTE_TOKENS color.

4. **Unassigned field validation overlay** — `isUnassigned` flag from `unassignedFieldIds.has(field.id)` applies `border: 2px solid #ef4444` / `background: #ef444414` to highlight fields needing signer assignment.

5. **Active signer selector UI** — Native `<select>` at `height: 32px` above field palette. Shows only when `!readOnly && signers.length > 0`. Colored dot indicator (8×8px circle in signer color). Label: "Active signer:" at 12px/500 weight.

6. **DragOverlay ghost** — Uses `activeSigner.color` for the ghost field color when an active signer is selected.

# Tech tracking
tech-stack:
  added: []
  removed: []
  changed: []

# Metrics
duration: 3min
commit: d768fc6
