docs(05-pdf-fill-and-field-mapping): create phase plan

.planning/ROADMAP.md

@@ -98,9 +98,13 @@ Plans:
   2. Signature field coordinates are stored in PDF user space (bottom-left origin) — verified by a unit test against an actual Utah real estate form
   3. Agent can fill in text fields (property address, client names, dates, prices) on the document before sending
   4. Agent can assign the prepared document to a specific client and initiate a signing request
-**Plans**: TBD
+**Plans**: 4 plans
 
-Plans: none yet
+Plans:
+- [ ] 05-01-PLAN.md — Schema extension (signatureFields, textFillData, assignedClientId, preparedFilePath JSONB columns), migration 0003, @cantoo/pdf-lib prepare utility, GET/PUT /api/documents/[id]/fields, POST /api/documents/[id]/prepare
+- [ ] 05-02-PLAN.md — dnd-kit FieldPlacer component: drag-and-drop signature field placement, Y-axis coordinate conversion, blue rectangle overlay, field persistence
+- [ ] 05-03-PLAN.md — TextFillForm + PreparePanel: key-value text fill form, client selector dropdown, Prepare and Send workflow
+- [ ] 05-04-PLAN.md — Full Phase 5 human verification checkpoint
 
 ### Phase 6: Signing Flow
 **Goal**: Client receives an email link, opens the prepared PDF in any browser, draws a signature, and the signed document is stored with a complete, legally defensible audit trail
@@ -142,6 +146,6 @@ Phases execute in numeric order: 1 → 2 → 3 → 4 → 5 → 6 → 7
 | 2. Marketing Site | 2/3 | In Progress|  |
 | 3. Agent Portal Shell | 4/4 | Complete   | 2026-03-19 |
 | 4. PDF Ingest | 4/4 | Complete   | 2026-03-20 |
-| 5. PDF Fill and Field Mapping | 0/? | Not started | - |
+| 5. PDF Fill and Field Mapping | 0/4 | Not started | - |
 | 6. Signing Flow | 0/? | Not started | - |
 | 7. Audit Trail and Download | 0/? | Not started | - |