docs(13-02): complete database schema plan

- SUMMARY.md with migration and model details
- STATE.md updated to Phase 13 Plan 2
- ROADMAP.md and REQUIREMENTS.md updated

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.planning/phases/13-link-discovery-registration-ingestion/13-02-SUMMARY.md

@@ -0,0 +1,95 @@
+---
+phase: 13-link-discovery-registration-ingestion
+plan: 02
+subsystem: database
+tags: [alembic, sqlalchemy, rls, wireless-links, device-interfaces, postgres]
+
+requires:
+  - phase: 12-wireless-registration-collection
+    provides: wireless_registrations hypertable and NATS stream
+provides:
+  - device_interfaces table with MAC-to-device resolution index
+  - wireless_links table with link state machine columns
+  - DeviceInterface and WirelessLink ORM models
+  - LinkState enum (discovered/active/degraded/down/stale)
+affects: [13-link-discovery-registration-ingestion]
+
+tech-stack:
+  added: []
+  patterns: [link state machine with missed_polls counter, MAC-indexed interface table]
+
+key-files:
+  created:
+    - backend/alembic/versions/032_device_interfaces_table.py
+    - backend/alembic/versions/033_wireless_links_table.py
+    - backend/app/models/device_interface.py
+    - backend/app/models/wireless_link.py
+  modified:
+    - backend/app/models/__init__.py
+
+key-decisions:
+  - "No backref on DeviceInterface.device relationship -- link discovery reads interfaces, does not navigate from Device to interfaces"
+
+patterns-established:
+  - "LinkState enum: discovered -> active -> degraded -> down -> stale state machine for wireless link health"
+  - "MAC-indexed interface table pattern for cross-device MAC resolution"
+
+requirements-completed: [LINK-02, LINK-03]
+
+duration: 2min
+completed: 2026-03-19
+---
+
+# Phase 13 Plan 02: Database Schema Summary
+
+**Alembic migrations and SQLAlchemy models for device_interfaces (MAC resolution) and wireless_links (AP-CPE state tracking) tables with RLS**
+
+## Performance
+
+- **Duration:** 2 min
+- **Started:** 2026-03-19T11:00:46Z
+- **Completed:** 2026-03-19T11:02:22Z
+- **Tasks:** 2
+- **Files modified:** 5
+
+## Accomplishments
+- device_interfaces table with MAC index for link discovery MAC-to-device resolution
+- wireless_links table with state machine columns (state, missed_polls) for AP-CPE tracking
+- Both tables have tenant isolation RLS matching codebase convention
+- DeviceInterface and WirelessLink models registered in app.models with LinkState enum
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Create device_interfaces table migration and ORM model** - `7147b15` (feat)
+2. **Task 2: Create wireless_links table migration, ORM model, and register both models** - `a71df2a` (feat)
+
+## Files Created/Modified
+- `backend/alembic/versions/032_device_interfaces_table.py` - device_interfaces table with RLS, MAC index, unique(device_id, name)
+- `backend/alembic/versions/033_wireless_links_table.py` - wireless_links table with state machine, missed_polls, 4 indexes, RLS
+- `backend/app/models/device_interface.py` - DeviceInterface ORM model with device relationship
+- `backend/app/models/wireless_link.py` - WirelessLink ORM model with LinkState enum, ap_device/cpe_device relationships
+- `backend/app/models/__init__.py` - Added DeviceInterface, WirelessLink, LinkState to model registry
+
+## Decisions Made
+- No backref on DeviceInterface.device relationship -- link discovery reads interfaces directionally, no need to navigate from Device to its interfaces via ORM
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Issues Encountered
+None
+
+## User Setup Required
+None - no external service configuration required.
+
+## Next Phase Readiness
+- device_interfaces and wireless_links tables ready for Plan 03's link discovery subscriber
+- LinkState enum available for state machine logic in the NATS subscriber
+- MAC index on device_interfaces enables efficient MAC-to-device lookups
+
+---
+*Phase: 13-link-discovery-registration-ingestion*
+*Completed: 2026-03-19*