0.3.0 update-docs updated

CHANGELOG.md

@@ -5,6 +5,65 @@ All notable changes to Seismo Fleet Manager 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).
 
+## [0.3.0] - 2025-12-09
+
+### Added
+- **Series 4 (Micromate) Support**: New `/api/series4/heartbeat` endpoint for receiving telemetry from Series 4 Micromate units
+  - Auto-detection of Series 4 units via UM##### ID pattern
+  - Stores project hints from emitter payload in unit notes
+  - Automatic unit type classification across both Series 3 and Series 4 endpoints
+- **Development Environment Labels**: Visual indicators to distinguish dev from production deployments
+  - Yellow "DEV" badge in sidebar navigation
+  - "[DEV]" prefix in browser title
+  - Yellow banner on dashboard when running in development mode
+  - Environment variable support in docker-compose.yml (ENVIRONMENT=production|development)
+- **Quality of Life Improvements**:
+  - Human-readable relative timestamps (e.g., "2h 15m ago", "3d ago") with full date in tooltips
+  - "Last Updated" timestamp indicator on dashboard
+  - Status icons for colorblind accessibility (checkmark for OK, clock for Pending, X for Missing)
+  - Breadcrumb navigation on unit detail pages
+  - Copy-to-clipboard buttons for unit IDs
+  - Search/filter functionality for fleet roster table
+  - Improved empty state messages with icons
+- **Timezone Support**: Comprehensive timezone handling across the application
+  - Timezone selector in Settings (defaults to America/New_York EST)
+  - Human-readable timestamp format (e.g., "9/10/2020 8:00 AM EST")
+  - Timezone-aware display for all timestamps site-wide
+  - Settings stored in localStorage for immediate effect
+- **Settings Page Redesign**: Complete overhaul with tabbed interface and persistent preferences
+  - **General Tab**: Display preferences (timezone, theme, auto-refresh interval)
+  - **Data Management Tab**: Safe operations (CSV export, merge import, roster table)
+  - **Advanced Tab**: Power user settings (replace mode import, calibration defaults, status thresholds)
+  - **Danger Zone Tab**: Destructive operations isolated with enhanced warnings
+  - Backend preferences storage via new UserPreferences model
+  - Tab state persistence in localStorage
+  - Smooth animations and consistent styling with existing pages
+- **User Preferences API**: New backend endpoints for persistent settings storage
+  - `GET /api/settings/preferences` - Retrieve all user preferences
+  - `PUT /api/settings/preferences` - Update preferences (supports partial updates)
+  - Database-backed storage for cross-device preference sync
+  - Migration script: `backend/migrate_add_user_preferences.py`
+
+### Changed
+- Timestamps now display in user-selected timezone with human-readable format throughout the application
+- Settings page reorganized from 644-line flat layout to clean 4-tab interface
+- CSV Replace Mode moved from Data Management to Advanced tab with additional warnings
+- Import operations separated: safe merge in Data Management tab, destructive replace in Advanced tab
+- Page title changed from "Roster Manager" to "Settings" for better clarity
+- All preferences now persist to backend database instead of relying solely on localStorage
+
+### Fixed
+- Unit type classification now consistent across Series 3 and Series 4 heartbeat endpoints
+- Auto-correction of misclassified unit types when they report to wrong endpoint
+
+### Technical Details
+- New `detect_unit_type()` helper function for pattern-based unit classification
+- UserPreferences model with single-row table pattern (id=1) for global settings
+- Series 4 units identified by UM prefix followed by digits (e.g., UM11719)
+- JavaScript Intl API used for client-side timezone conversion
+- Pydantic schema for partial preference updates (PreferencesUpdate model)
+- Environment context injection via custom FastAPI template response wrapper
+
 ## [0.2.1] - 2025-12-03
 
 ### Added
@@ -92,6 +151,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Photo management per unit
 - Automated status categorization (OK/Pending/Missing)
 
+[0.3.0]: https://github.com/serversdwn/seismo-fleet-manager/compare/v0.2.1...v0.3.0
 [0.2.1]: https://github.com/serversdwn/seismo-fleet-manager/compare/v0.2.0...v0.2.1
 [0.2.0]: https://github.com/serversdwn/seismo-fleet-manager/compare/v0.1.1...v0.2.0
 [0.1.1]: https://github.com/serversdwn/seismo-fleet-manager/compare/v0.1.0...v0.1.1