feat(phase-2): school registry + license management UI

Plan 2-01: School create/edit modal + license editor
- SchoolsPage: full create/edit modal (name, city, address, tier, contact,
  billing email, SMS sender name, student limit, status, notes); debounced
  search + status filter; Edit button per row opens pre-filled modal
- SchoolDetailPage: Activate / Suspend / Edit quick-action buttons in header;
  license panel with key copy, expiry, last seen (time-ago); license editor
  (expiry date, max students, tier) calls PUT /api/licenses/{id}; Revoke
  button calls POST /api/licenses/{id}/revoke
- Backend: GET /api/licenses/school/{school_id} — fetch license by school
- api.ts: getSchoolLicense added

Plan 2-02: Subscription setup + SMS credit top-up + ledger
- SchoolDetailPage: subscription panel (monthly fee, SMS cost per msg,
  billing cycle, next billing date) upserts via billing API
- SMS Credits panel: color-coded credit meter (green/amber/red based on
  balance), preset +100/+500/+1000 buttons, custom amount + note field,
  recent 5 ledger entries, link to full SMS page
- All operations toast on success/error

PAUL: Phase 2 marked complete, STATE + ROADMAP updated

.paul/ROADMAP.md

@@ -19,8 +19,8 @@ SMS flow: On-prem TapTrack polls Hub every 30s → Hub queues SMS jobs → Hub s
 ## Current Milestone
 
 **v1.0 — Foundation & Core Services**
-Status: Phase 1 complete — Phase 2 next
-Phases: 1 of 15 complete
+Status: Phase 2 complete — Phase 3 next
+Phases: 2 of 15 complete
 
 ---
 
@@ -29,7 +29,7 @@ Phases: 1 of 15 complete
 | Phase | Name                         | Plans | Status       | Completed  |
 |-------|------------------------------|-------|--------------|------------|
 | 1     | Project Setup & Infrastructure | 1   | ✅ Complete  | 2026-03-15 |
-| 2     | School Registry + License Mgmt | TBD | Not started  | —          |
+| 2     | School Registry + License Mgmt | 2   | ✅ Complete  | 2026-03-15 |
 | 3     | On-Prem License Validation     | TBD | Not started  | —          |
 | 4     | SMS Gateway (credits + queue)  | TBD | Not started  | —          |
 | 5     | On-Prem SMS Polling Agent      | TBD | Not started  | —          |