Improve timestamp handling and event navigation

deploy/README.md

@@ -10,6 +10,8 @@ MONLET_AUTH_TOKEN=$(openssl rand -hex 16) docker compose up --build
 ```
 
 Brings up: PostgreSQL 16, Monlet server (with Alembic upgrade on start), Web UI.
+Web timestamps use `MONLET_WEB_TIME_ZONE` (`UTC` by default); notification text/annotations use `MONLET_NOTIFICATION_TIME_ZONE` (`UTC` by default).
+PostgreSQL and server containers run with `TZ=UTC`; local presentation timezones are configured separately.
 
 - Server: http://127.0.0.1:8000 (`/api/v1/health`, `/api/v1/ready`, `/metrics`)
 - Web UI: http://127.0.0.1:3000

deploy/docker-compose.yml

@@ -5,6 +5,7 @@ services:
       POSTGRES_USER: monlet
       POSTGRES_PASSWORD: monlet
       POSTGRES_DB: monlet
+      TZ: UTC
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -U monlet -d monlet"]
       interval: 5s
@@ -27,7 +28,9 @@ services:
       MONLET_LOG_LEVEL: ${MONLET_LOG_LEVEL:-INFO}
       MONLET_ENABLE_DETECTOR: "true"
       MONLET_ENABLE_NOTIFIER_WORKER: "true"
+      MONLET_NOTIFICATION_TIME_ZONE: ${MONLET_NOTIFICATION_TIME_ZONE:-UTC}
       MONLET_NOTIFIER_DEBUG_ENABLED: "true"
+      TZ: UTC
     command:
       - sh
       - -c
@@ -49,6 +52,8 @@ services:
     environment:
       MONLET_API_BASE_URL: http://server:8000
       MONLET_API_TOKEN: ${MONLET_AUTH_TOKEN:?MONLET_AUTH_TOKEN is required}
+      MONLET_WEB_TIME_ZONE: ${MONLET_WEB_TIME_ZONE:-UTC}
+      TZ: ${MONLET_WEB_TIME_ZONE:-UTC}
     ports:
       - "3000:3000"