docs(18-01): complete template schema plan — documentTemplates table + migration 0012

- SUMMARY.md created for phase 18 plan 01
- STATE.md: plan advanced to 18-02, progress 97%, decisions recorded
- ROADMAP.md: phase 18 progress updated (1/2 plans complete)
- REQUIREMENTS.md: TMPL-01 marked complete

.planning/phases/18-template-schema-and-crud-api/18-01-SUMMARY.md

@@ -0,0 +1,77 @@
+---
+phase: 18-template-schema-and-crud-api
+plan: "01"
+subsystem: database-schema
+tags: [drizzle, schema, migration, postgresql]
+dependency_graph:
+  requires: [formTemplates table (form_templates), SignatureFieldData interface]
+  provides: [documentTemplates table (document_templates), documentTemplatesRelations]
+  affects: [Phase 19 template editor, Phase 20 apply-template endpoint]
+tech_stack:
+  added: []
+  patterns: [drizzle pgTable, jsonb $type, nullable timestamp soft-delete, FK no-cascade]
+key_files:
+  created:
+    - teressa-copeland-homes/drizzle/0012_ancient_blue_shield.sql
+  modified:
+    - teressa-copeland-homes/src/lib/db/schema.ts
+decisions:
+  - "signatureFields nullable JSONB: template starts empty; Phase 19 fills it via PATCH"
+  - "formTemplateId FK has no onDelete cascade: archived templates remain even if form is removed"
+  - "archivedAt nullable timestamp: NULL = active; soft-delete only (no hard deletes)"
+  - "updatedAt set explicitly in UPDATE queries, not via DB trigger (existing pattern)"
+metrics:
+  duration: "4 min"
+  completed_date: "2026-04-06"
+  tasks_completed: 2
+  files_changed: 2
+---
+
+# Phase 18 Plan 01: Template Schema and Migration Summary
+
+**One-liner:** Drizzle `document_templates` table with 7 columns, nullable JSONB fields, soft-delete via `archivedAt`, FK to `form_templates` with no cascade, and auto-generated SQL migration 0012.
+
+## Tasks Completed
+
+| Task | Name | Commit | Files |
+|------|------|--------|-------|
+| 1 | Add documentTemplates table to schema.ts | 9e677f9 | teressa-copeland-homes/src/lib/db/schema.ts |
+| 2 | Generate Drizzle migration | c33c4ec | teressa-copeland-homes/drizzle/0012_ancient_blue_shield.sql |
+
+## What Was Built
+
+Added the `documentTemplates` Drizzle table definition to `schema.ts` immediately after `formTemplates`. The table has exactly 7 columns per D-02:
+
+- `id` — TEXT PRIMARY KEY via `crypto.randomUUID()`
+- `name` — TEXT NOT NULL
+- `formTemplateId` — TEXT NOT NULL, FK to `formTemplates.id` with no `onDelete` (D-06)
+- `signatureFields` — JSONB nullable, typed as `SignatureFieldData[]` (D-04)
+- `archivedAt` — TIMESTAMP nullable, soft-delete sentinel (D-07)
+- `createdAt` — TIMESTAMP NOT NULL DEFAULT NOW()
+- `updatedAt` — TIMESTAMP NOT NULL DEFAULT NOW()
+
+Also added `documentTemplatesRelations` joining to `formTemplates` via `formTemplateId`.
+
+Generated migration `0012_ancient_blue_shield.sql` via `drizzle-kit generate`. The migration contains only a `CREATE TABLE` statement and an `ALTER TABLE ... ADD CONSTRAINT` for the FK — no alterations to existing tables.
+
+## Verification
+
+- `npx tsc --noEmit` — zero errors
+- `ls drizzle/0012_*.sql` — exactly one migration file (0012_ancient_blue_shield.sql)
+- `grep "document_templates" drizzle/0012_ancient_blue_shield.sql` — CREATE TABLE present
+- `grep "form_template_id" drizzle/0012_ancient_blue_shield.sql` — FK column present
+
+## Deviations from Plan
+
+None — plan executed exactly as written.
+
+## Known Stubs
+
+None — this plan is schema-only. No UI or API routes were implemented. Phase 18-02 handles the CRUD API routes.
+
+## Self-Check: PASSED
+
+- `teressa-copeland-homes/src/lib/db/schema.ts` — FOUND, contains documentTemplates export
+- `teressa-copeland-homes/drizzle/0012_ancient_blue_shield.sql` — FOUND, contains CREATE TABLE document_templates
+- Commit 9e677f9 — FOUND
+- Commit c33c4ec — FOUND