feat: add location_slots to job_reservations for full slot persistence and update version to 0.9.1

Fix: modems do not show as "missing" any more, cleans up the dashboard.

CHANGELOG.md

@@ -5,6 +5,20 @@ All notable changes to Terra-View will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.9.1] - 2026-03-23
+
+### Fixed
+- **Location slots not persisting**: Empty monitoring location slots (no unit assigned yet) were lost on save/reload. Added `location_slots` JSON column to `job_reservations` to store the full slot list including empty slots.
+- **Modems in Recent Alerts**: Modems no longer appear in the dashboard Recent Alerts panel — alerts are for seismographs and SLMs only. Modem status is still tracked internally via paired device inheritance.
+
+### Migration Notes
+Run on each database before deploying:
+```bash
+docker compose exec terra-view python3 backend/migrate_add_location_slots.py
+```
+
+---
+
 ## [0.9.0] - 2026-03-19
 
 ### Added