Initial commit: Chrony NTP Server add-on for Home Assistant

- NTP client syncs from configurable pools and servers
- NTP server mode serves time to LAN clients
- Web UI dashboard showing sync status, sources, and clients
- Supports iburst and maxsources options

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

chrony-addon/config.yaml

@@ -0,0 +1,49 @@
+name: "Chrony NTP Server"
+description: "NTP server and client using Chrony for accurate time synchronization"
+version: "1.0"
+slug: "chrony-addon"
+#image: "local/chrony-{arch}"
+init: false
+arch:
+  - amd64
+  - aarch64
+host_network: true
+privileged:
+  - SYS_TIME
+webui: "http://[HOST]:[PORT:8099]"
+ingress: true
+ingress_port: 8099
+ingress_stream: false
+panel_icon: "mdi:clock-sync"
+panel_title: "Chrony NTP"
+map:
+  - config:rw
+options:
+  ntp_pools:
+    - pool: "pool.ntp.org"
+      iburst: true
+  ntp_servers:
+    - server: "time.google.com"
+      iburst: true
+  allow_clients:
+    - "192.168.0.0/16"
+    - "10.0.0.0/8"
+    - "172.16.0.0/12"
+  enable_ntp_server: true
+  detailed_logging: false
+schema:
+  ntp_pools:
+    - pool: str
+      iburst: bool?
+      maxsources: int(1,16)?
+  ntp_servers:
+    - server: str
+      iburst: bool?
+  allow_clients:
+    - str
+  enable_ntp_server: bool
+  detailed_logging: bool
+ports:
+  123/udp: 123
+ports_description:
+  123/udp: "NTP service"