docs(02-03): complete Subscriber and ServicePlan management plan

Tasks completed: 2/2
- Task 1: Subscriber and ServicePlan Prisma models + service layer
- Task 2: Subscriber and ServicePlan API routes + tests

SUMMARY: .planning/phases/02-subscriber-and-billing-core/02-03-SUMMARY.md

.planning/STATE.md

@@ -10,11 +10,11 @@ See: .planning/PROJECT.md (updated 2026-03-04)
 ## Current Position
 
 Phase: 2 of 5 (Subscriber and Billing Core) — In progress
-Plan: 1 of 5 in phase 2 complete (6/20 total)
+Plan: 3 of 5 in phase 2 complete (8/20 total)
-Status: In progress. 02-01 (COA + Accounting Periods) complete.
+Status: In progress. 02-01 (COA + Accounting Periods) and 02-03 (Subscriber + ServicePlan) complete.
-Last activity: 2026-03-04 — Completed 02-01-PLAN.md (ISP Chart of Accounts, accounting period management, 121 tests)
+Last activity: 2026-03-04 — Completed 02-03-PLAN.md (Subscriber management, service plans, 41 new tests, 162 total)
 
-Progress: [██████░░░░] 30% (6/20 plans across all phases)
+Progress: [████████░░] 40% (8/20 plans across all phases)
 
 ## Performance Metrics
 
@@ -28,10 +28,10 @@ Progress: [██████░░░░] 30% (6/20 plans across all phases)
 | Phase | Plans | Total | Avg/Plan |
 |-------|-------|-------|----------|
 | 01-foundation | 5/5 complete | 41 min | 8.2 min |
-| 02-subscriber-and-billing-core | 1/5 complete | 7 min | 7 min |
+| 02-subscriber-and-billing-core | 3/5 complete | 21 min | 7 min |
 
 **Recent Trend:**
-- Last 6 plans: 01-01 (11 min), 01-02 (8 min), 01-03 (9 min), 01-04 (7 min), 01-05 (6 min), 02-01 (7 min)
+- Last 7 plans: 01-01 (11 min), 01-02 (8 min), 01-03 (9 min), 01-04 (7 min), 01-05 (6 min), 02-01 (7 min), 02-03 (7 min)
 - Trend: stable around 7-8 min
 
 *Updated after each plan completion*
@@ -74,6 +74,10 @@ Recent decisions affecting current work:
 - [02-01]: seedChartOfAccounts receives Prisma tx client — works inside createTenant $transaction for atomic provisioning
 - [02-01]: Accounting periods created on-demand via getOpenPeriod() — not pre-seeded on signup (no wasted periods for unused months)
 - [02-01]: close route uses closure pattern over withPermission HOF — withPermission doesn't support dynamic params directly; POST fn closes over Next.js params
+- [02-03]: creditBalance on Subscriber is operational convenience (FIFO credit allocation for 02-05), NOT a ledger balance — always updated atomically with journal entries
+- [02-03]: billingDay capped at 28 — subscribers signing up on days 29-31 get billingDay=28 to avoid month-length invoice generation issues
+- [02-03]: CANCELLED -> ACTIVE transition is reversible by design — ISPs frequently reinstate cancelled accounts per CONTEXT.md
+- [02-03]: as any cast in service create() calls — Prisma static type requires tenantId but withTenantContext() extension injects at runtime; cast is intentional
 
 ### Pending Todos
 
@@ -88,6 +92,6 @@ None.
 
 ## Session Continuity
 
-Last session: 2026-03-04T14:51:56Z
+Last session: 2026-03-04T15:02:45Z
-Stopped at: Completed 02-01-PLAN.md (COA + accounting period management + 28 new tests, 121 total)
+Stopped at: Completed 02-03-PLAN.md (Subscriber + ServicePlan management + 41 new tests, 162 total)
 Resume file: None

.planning/phases/02-subscriber-and-billing-core/02-03-SUMMARY.md

@@ -0,0 +1,144 @@
+---
+phase: 02-subscriber-and-billing-core
+plan: "03"
+subsystem: database
+tags: [prisma, postgresql, subscriber, billing, service-plans, tenant-isolation]
+
+# Dependency graph
+requires:
+  - phase: 02-subscriber-and-billing-core/02-01
+    provides: Prisma setup, withTenantContext HOF, COA models — established patterns reused here
+  - phase: 01-foundation/01-03
+    provides: prisma-tenant.ts TENANT_SCOPED_MODELS pattern extended with new models
+  - phase: 01-foundation/01-04
+    provides: withPermission HOF wrapping API routes
+provides:
+  - Subscriber Prisma model with accountNumber, status lifecycle, billingDay, creditBalance
+  - ServicePlan Prisma model with name, speed, monthlyPrice, billingType, soft-delete
+  - TenantSettings Prisma model with autoSuspendDays and prepaidLeadDays
+  - subscriber-service.ts with createSubscriber, updateSubscriber, changeSubscriberStatus, searchSubscribers, getSubscriber
+  - service-plan-service.ts with createServicePlan, updateServicePlan, listServicePlans, deactivateServicePlan
+  - Full REST API for subscribers and service plans
+  - 41 integration tests (162 total passing)
+affects:
+  - 02-04-billing-engine (Subscriber and ServicePlan are the billing targets)
+  - 02-05-payment-allocation (creditBalance field on Subscriber for FIFO allocation)
+  - 03-collector-app (zone field on Subscriber for collector routing)
+  - 04-inventory (subscriber association)
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns:
+    - Closure pattern for dynamic route params with withPermission HOF
+    - as any cast for Prisma create() data when tenantId injected by extension
+    - Soft-delete pattern via isActive boolean on ServicePlan
+    - Reversible status lifecycle with explicit transition validation matrix
+
+key-files:
+  created:
+    - prisma/migrations/20260304145633_add_subscriber_models/migration.sql
+    - src/lib/services/service-plan-service.ts
+    - src/lib/services/subscriber-service.ts
+    - src/app/api/service-plans/route.ts
+    - src/app/api/service-plans/[id]/route.ts
+    - src/app/api/subscribers/route.ts
+    - src/app/api/subscribers/[id]/route.ts
+    - src/app/api/subscribers/[id]/status/route.ts
+    - src/lib/__tests__/subscriber.test.ts
+  modified:
+    - prisma/schema.prisma
+    - src/lib/prisma-tenant.ts
+
+key-decisions:
+  - "creditBalance on Subscriber is NOT a ledger balance — it is an operational convenience field for FIFO overpayment credit allocation (02-05), always updated atomically with journal entries"
+  - "billingDay capped at 28 — avoids month-length issues (no SUB-0001 billed on Feb 29 that doesn't exist)"
+  - "CANCELLED -> ACTIVE reversible by design (per CONTEXT.md) — ISPs frequently reinstate cancelled accounts"
+  - "Closure pattern for dynamic params — withPermission HOF signature doesn't pass params; outer fn receives them from Next.js then inner handler uses via closure (same as accounting/periods/[id]/close pattern)"
+  - "as any cast in create() calls — Prisma static type requires tenantId but withTenantContext() extension injects it at runtime; cast is intentional and safe"
+
+patterns-established:
+  - "Closure pattern for dynamic params: export function PUT(req, { params }) { return withPermission(...)(async (req, { user }) => { const { id } = await params; ... })(req); }"
+  - "Service layer takes TenantPrisma (ReturnType<typeof withTenantContext>) — never takes tenantId directly, always scoped client"
+  - "Status transition matrix: Record<SubscriberStatus, SubscriberStatus[]> — explicit, exhaustive, easily auditable"
+  - "generateAccountNumber queries max accountNumber and increments — sequential per tenant, format SUB-NNNN"
+
+# Metrics
+duration: 7min
+completed: 2026-03-04
+---
+
+# Phase 2 Plan 03: Subscriber and ServicePlan Management Summary
+
+**Subscriber and ServicePlan Prisma models with full CRUD, status lifecycle (ACTIVE/SUSPENDED/CANCELLED all reversible), sequential account numbers (SUB-0001+), billingDay from signup date, and paginated search/filter — the core billing targets for 02-04**
+
+## Performance
+
+- **Duration:** 7 min
+- **Started:** 2026-03-04T14:55:45Z
+- **Completed:** 2026-03-04T15:02:45Z
+- **Tasks:** 2/2
+- **Files modified:** 11
+
+## Accomplishments
+
+- Subscriber and ServicePlan Prisma models with full migration applied to database
+- TenantSettings model for per-tenant autoSuspendDays and prepaidLeadDays configuration
+- Complete service layer: subscriber CRUD, status lifecycle transitions, plan CRUD with soft-delete
+- Full REST API (7 endpoints) with closure pattern for dynamic routes
+- 41 new integration tests covering all lifecycle transitions, search/filter, pagination, and tenant isolation
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Subscriber and ServicePlan Prisma models + service layer** - `9cc6af1` (feat)
+2. **Task 2: Subscriber and ServicePlan API routes + tests** - `03a4a29` (feat)
+
+**Plan metadata:** (docs commit follows)
+
+## Files Created/Modified
+
+- `prisma/schema.prisma` - Added SubscriberStatus, BillingType enums; ServicePlan, Subscriber, TenantSettings models
+- `prisma/migrations/20260304145633_add_subscriber_models/migration.sql` - Database migration
+- `src/lib/prisma-tenant.ts` - Extended TENANT_SCOPED_MODELS and query blocks for subscriber, servicePlan, tenantSettings
+- `src/lib/services/service-plan-service.ts` - createServicePlan, updateServicePlan, listServicePlans, deactivateServicePlan
+- `src/lib/services/subscriber-service.ts` - createSubscriber, updateSubscriber, changeSubscriberStatus, searchSubscribers, getSubscriber, generateAccountNumber
+- `src/app/api/service-plans/route.ts` - GET (list with activeOnly filter), POST (create)
+- `src/app/api/service-plans/[id]/route.ts` - PUT (partial update)
+- `src/app/api/subscribers/route.ts` - GET (paginated search with filters), POST (register)
+- `src/app/api/subscribers/[id]/route.ts` - GET (with servicePlan relation), PUT (profile update)
+- `src/app/api/subscribers/[id]/status/route.ts` - PATCH (status lifecycle transitions)
+- `src/lib/__tests__/subscriber.test.ts` - 41 integration tests
+
+## Decisions Made
+
+- **creditBalance as operational convenience field** — Distinguishing from "no mutable balance fields" rule: creditBalance tracks overpayment credits for FIFO allocation (02-05), always updated atomically with journal entries. Architectural mutable balance fields (account balances) remain journal-derived.
+- **billingDay capped at 28** — Subscribers who sign up on day 29, 30, or 31 get billingDay=28 to avoid month-length boundary issues with invoice generation.
+- **Reversible CANCELLED -> ACTIVE transition** — Per CONTEXT.md, ISPs frequently reinstate cancelled accounts. No one-way door on cancellation.
+- **Closure pattern for dynamic params** — `withPermission` HOF doesn't pass Next.js route params to handlers. Using closure pattern (same as accounting/periods/[id]/close) instead of modifying the HOF.
+- **as any cast in create() calls** — The Prisma extended client injects tenantId at runtime but static types still require it. Safe to cast since the extension guarantees injection.
+
+## Deviations from Plan
+
+None — plan executed exactly as written.
+
+## Issues Encountered
+
+None.
+
+## User Setup Required
+
+None — no external service configuration required.
+
+## Next Phase Readiness
+
+- Subscriber and ServicePlan models ready for 02-04 billing engine (invoice generation targets)
+- creditBalance field on Subscriber ready for 02-05 FIFO payment allocation
+- zone field on Subscriber ready for Phase 3 collector routing
+- TenantSettings provides autoSuspendDays for auto-suspension logic in billing engine
+- All tenant isolation verified: Subscriber/ServicePlan data not visible across tenants
+
+---
+*Phase: 02-subscriber-and-billing-core*
+*Completed: 2026-03-04*