docs(08-01): complete schema foundation plan — SignatureFieldType discriminant

- Create 08-01-SUMMARY.md with full task documentation and deviation notes
- Update STATE.md: plan 1 of 2 complete, decisions recorded, session updated
- Update ROADMAP.md: phase 8 progress 1/2, 08-01-PLAN.md marked complete

.planning/phases/08-schema-foundation-and-signing-page-safety/08-01-SUMMARY.md

@@ -0,0 +1,99 @@
+---
+phase: 08-schema-foundation-and-signing-page-safety
+plan: "01"
+subsystem: schema
+tags: [schema, typescript, drizzle, field-types, backward-compat]
+dependency_graph:
+  requires: []
+  provides:
+    - SignatureFieldType union type
+    - getFieldType() helper function
+    - isClientVisibleField() predicate function
+    - Drizzle migration snapshot 0006
+  affects:
+    - teressa-copeland-homes/src/lib/db/schema.ts
+    - teressa-copeland-homes/drizzle/meta/_journal.json
+tech_stack:
+  added: []
+  patterns:
+    - TypeScript union type discriminant for JSONB field data
+    - Backward-compatible optional field with coalescing helper
+key_files:
+  created:
+    - teressa-copeland-homes/drizzle/0006_type_discriminant.sql
+    - teressa-copeland-homes/drizzle/meta/0006_snapshot.json
+  modified:
+    - teressa-copeland-homes/src/lib/db/schema.ts
+    - teressa-copeland-homes/drizzle/meta/_journal.json
+decisions:
+  - "SignatureFieldType field on SignatureFieldData is optional to preserve backward-compat with v1.0 documents that have no type in their JSONB data"
+  - "getFieldType() coalesces field.type ?? 'client-signature' so all v1.0 documents resolve as client-signature without any data migration"
+  - "isClientVisibleField() returns false only for agent-signature — all other types (including undefined/legacy) are visible to client"
+  - "Migration 0006 has no DDL — .$type<T>() is TypeScript-only; snapshot and journal updated manually since Drizzle declined to generate (no DDL changes)"
+  - "db:migrate skipped — database unavailable in dev environment; migration is a no-op and presents no risk"
+metrics:
+  duration: "2 min"
+  completed: "2026-03-21"
+  tasks_completed: 2
+  files_modified: 4
+---
+
+# Phase 8 Plan 01: Schema Foundation — SignatureFieldType Discriminant Summary
+
+**One-liner:** TypeScript-only schema discriminant adding SignatureFieldType union, optional type field on SignatureFieldData, and two backward-compatible helper exports (getFieldType, isClientVisibleField).
+
+## What Was Built
+
+Extended `teressa-copeland-homes/src/lib/db/schema.ts` with three additions required by all Phase 9-13 field-type features:
+
+1. **`SignatureFieldType` union type** — six literals: `'client-signature' | 'initials' | 'text' | 'checkbox' | 'date' | 'agent-signature'`
+
+2. **`SignatureFieldData.type?` field** — optional field on the existing interface; v1.0 documents with no type continue to work without data migration
+
+3. **`getFieldType(field)` helper** — always returns a `SignatureFieldType`, coalescing `field.type ?? 'client-signature'`; prevents scattered `field.type ?? 'client-signature'` patterns across call sites
+
+4. **`isClientVisibleField(field)` predicate** — returns `false` for `agent-signature` only, used by the signing page filter added in Plan 08-02
+
+Created `drizzle/0006_type_discriminant.sql` (empty SQL — no DDL) and updated `drizzle/meta/_journal.json` and `drizzle/meta/0006_snapshot.json` to keep the Drizzle migration chain in sync.
+
+## Commits
+
+| Task | Commit | Files |
+|------|--------|-------|
+| 1: Extend schema.ts | `2dd1b61` | `src/lib/db/schema.ts` |
+| 2: Migration snapshot | `b5f8b62` | `drizzle/0006_type_discriminant.sql`, `drizzle/meta/0006_snapshot.json`, `drizzle/meta/_journal.json` |
+
+## Deviations from Plan
+
+### Manual migration file creation
+
+**Found during:** Task 2
+
+**Issue:** `npm run db:generate` reported "No schema changes, nothing to migrate" because `SignatureFieldType` is a TypeScript-only change (`.$type<T>()` annotation) with no DDL. Drizzle does not create a migration file when there are no DDL changes.
+
+**Fix:** Created `drizzle/0006_type_discriminant.sql` (comment-only, no SQL), `drizzle/meta/0006_snapshot.json` (DDL state identical to 0005), and updated `_journal.json` manually. This matches the plan's stated intent: "The SQL content will be empty or contain only a comment — that is CORRECT and expected."
+
+**Files modified:** `drizzle/0006_type_discriminant.sql` (created), `drizzle/meta/0006_snapshot.json` (created), `drizzle/meta/_journal.json` (updated)
+
+**Rule:** Rule 3 — Auto-fix blocking issue (Drizzle would not auto-generate the required file)
+
+### db:migrate not applied
+
+**Found during:** Task 2
+
+**Issue:** `npm run db:migrate` failed with "url: undefined" — no database connection string configured in environment.
+
+**Resolution:** Noted in summary as planned. The plan explicitly states this is acceptable: "DO NOT block plan completion — the TypeScript changes are the deliverable." Migration is a no-op (empty SQL) and presents no risk.
+
+## Self-Check: PASSED
+
+Files exist:
+- FOUND: `teressa-copeland-homes/src/lib/db/schema.ts`
+- FOUND: `teressa-copeland-homes/drizzle/0006_type_discriminant.sql`
+- FOUND: `teressa-copeland-homes/drizzle/meta/0006_snapshot.json`
+
+Commits exist:
+- FOUND: `2dd1b61` feat(08-01): extend SignatureFieldData with type discriminant and helper exports
+- FOUND: `b5f8b62` chore(08-01): add Drizzle migration snapshot for TypeScript-only schema change
+
+TypeScript compilation: PASS (npx tsc --noEmit exits 0)