docs(14-01): complete multi-signer schema plan — migration 0010 applied

- SUMMARY.md: 2 tasks complete, schema.ts + migration 0010 committed
- STATE.md: advanced to plan 1 complete, decisions logged, 98% progress
- ROADMAP.md: phase 14 marked Complete (1/1 plans)
- REQUIREMENTS.md: MSIGN-08 marked complete

.planning/phases/14-multi-signer-schema/14-01-SUMMARY.md

@@ -0,0 +1,85 @@
+---
+phase: 14-multi-signer-schema
+plan: "01"
+subsystem: database-schema
+tags: [schema, drizzle, multi-signer, migration]
+dependency_graph:
+  requires: []
+  provides: [multi-signer-schema-columns, DocumentSigner-interface, getSignerEmail-helper]
+  affects: [phase-15-backend, phase-16-ui]
+tech_stack:
+  added: []
+  patterns: [additive-nullable-columns, jsonb-typed-columns, safe-reader-helper]
+key_files:
+  created:
+    - teressa-copeland-homes/drizzle/0010_sharp_archangel.sql
+    - teressa-copeland-homes/drizzle/meta/0010_snapshot.json
+  modified:
+    - teressa-copeland-homes/src/lib/db/schema.ts
+decisions:
+  - "documents.signers JSONB shape is { email, color }[] — not string[] — so Phase 16 can retrieve consistent per-signer colors from DB without recalculating"
+  - "signingTokens.signerEmail is nullable TEXT — NULL = legacy single-signer token, no existing token creation code requires changes"
+  - "documents.completionTriggeredAt is nullable TIMESTAMP used as atomic completion guard in Phase 15 UPDATE...WHERE completionTriggeredAt IS NULL"
+  - "SignatureFieldData.signerEmail? follows exact same additive-nullable pattern as type? — zero breakage to existing JSONB field rows"
+  - "No Partially Signed status added to documentStatusEnum — partial state computed dynamically in Phase 16 by counting used tokens"
+metrics:
+  duration: "5 min"
+  completed_date: "2026-04-03"
+  tasks_completed: 2
+  files_modified: 3
+---
+
+# Phase 14 Plan 01: Multi-Signer Schema Summary
+
+Additive Drizzle migration 0010 adding signerEmail to SignatureFieldData and signingTokens, plus signers JSONB and completionTriggeredAt to documents — all nullable, zero backfills, TypeScript compiles cleanly.
+
+## What Was Built
+
+Three new nullable database columns and one TypeScript interface extension, establishing the data foundation for Phases 15 (sign handler rewrite) and 16 (multi-signer UI):
+
+1. `SignatureFieldData.signerEmail?: string` — optional field ownership routing (absent = legacy single-signer)
+2. `getSignerEmail(field, fallbackEmail)` helper — safe reader following the same pattern as `getFieldType()`
+3. `DocumentSigner` interface — `{ email: string; color: string }[]` shape for the signers JSONB array
+4. `documents.signers JSONB` — per-signer list with assigned colors; NULL = legacy single-signer document
+5. `documents.completionTriggeredAt TIMESTAMP` — atomic completion guard for Phase 15's race-safe handler
+6. `signingTokens.signerEmail TEXT` — per-token signer identity; NULL = legacy single-signer token
+
+Migration `0010_sharp_archangel.sql` contains exactly 3 `ALTER TABLE...ADD COLUMN` statements — no DROPs, no ALTER TYPEs, no backfills.
+
+## Tasks
+
+| Task | Name | Commit | Files |
+|------|------|--------|-------|
+| 1 | Add multi-signer types and columns to schema.ts | c658f13 | src/lib/db/schema.ts |
+| 2 | Generate Drizzle migration and apply it | 3639491 | drizzle/0010_sharp_archangel.sql, drizzle/meta/_journal.json, drizzle/meta/0010_snapshot.json |
+
+## Decisions Made
+
+- `documents.signers` uses `{ email, color }[]` JSONB shape so Phase 16 PreparePanel can render consistent signer-assigned colors without recalculating by index position
+- `signerEmail` on `SignatureFieldData` is optional (not required) so every existing JSONB field row stored in the DB remains valid with no migration needed
+- `completionTriggeredAt` is Phase 14 schema-only; write logic (UPDATE...WHERE...IS NULL RETURNING) is Phase 15 scope
+- No `Partially Signed` enum value added — computed dynamically by counting `usedAt IS NOT NULL` tokens in Phase 16
+
+## Verification Results
+
+- `npx tsc --noEmit` exits 0 — no TypeScript errors
+- `grep -c signerEmail src/lib/db/schema.ts` returns 6 (>= 3 required)
+- Migration SQL contains only `ALTER TABLE...ADD COLUMN` — no DROPs
+- Migration applied successfully to local Postgres instance
+- No files outside schema.ts and drizzle/ were modified
+
+## Deviations from Plan
+
+None — plan executed exactly as written.
+
+## Known Stubs
+
+None — this plan is schema-only with no UI or data-rendering code paths.
+
+## Self-Check: PASSED
+
+- `teressa-copeland-homes/src/lib/db/schema.ts` — FOUND (modified)
+- `teressa-copeland-homes/drizzle/0010_sharp_archangel.sql` — FOUND (created)
+- `teressa-copeland-homes/drizzle/meta/0010_snapshot.json` — FOUND (created)
+- Commit c658f13 — FOUND
+- Commit 3639491 — FOUND