docs: Clean up stale docs, add CHANGELOG

- Remove completed items from TODO.md (OSINT, fleet, collector done)
- Move TASKS.md sprint to v0.1.4, archive v0.1.3 as complete
- Create CHANGELOG.md covering v0.1.0 through v0.1.3

CHANGELOG.md

@@ -0,0 +1,44 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+## [v0.1.3] - 2026-02-05
+
+### Added
+- Sensor config endpoints (GET/PUT `/api/v1/sensors/<id>/config`)
+- OTA trigger endpoint (`POST /api/v1/sensors/<id>/ota`)
+- Calibration trigger endpoint (`POST /api/v1/sensors/<id>/calibrate`)
+- Heartbeat timeout detection (marks sensors offline)
+- Sensor metrics history endpoint
+- OpenAPI 3.0 spec with Swagger UI at `/api/docs`
+
+## [v0.1.2] - 2026-02-05
+
+### Added
+- IEEE OUI database download (`make oui`)
+- MAC vendor lookup utility
+- BLE company_id to manufacturer mapping (30+ vendors)
+- Device profile enrichment in API responses
+- Export endpoints: devices.csv, devices.json, alerts.csv, probes.csv
+- Auto-populate vendor field on device creation
+
+## [v0.1.1] - 2026-02-05
+
+### Added
+- Makefile start/stop/restart/status commands
+- Health endpoint with uptime tracking (`/api/v1/health`)
+- CLI module (`esp32-web` command)
+- Database migrations via Flask-Migrate
+- Listen on all interfaces (0.0.0.0:5500)
+- `make help` target
+
+## [v0.1.0] - 2026-02-05
+
+### Added
+- Flask app factory with blueprint architecture
+- SQLAlchemy 2.x models: Sensor, Device, Sighting, Alert, Event, Probe
+- REST API endpoints for all models
+- UDP collector with data stream parsers
+- pytest fixtures and initial tests
+- Containerfile for podman
+- Makefile for common tasks