feat(cameras): add sky-cam and frigate-audio service modules

sky-cam (cameras/non-docker):
  Clones outis1one/sky-cam via bootstrap.sh to ~/sky-cam. Prompts for
  latitude, longitude, timezone, camera names, BASE_DIR, and optional
  Mattermost webhook. Patches sky-cam.conf and installs systemd user
  timers via the repo's install.sh. Produces sunrise clips, Four Seasons
  timelapse, moon-track, and monthly moon-phase images.

frigate-audio (cameras/docker):
  Full stack from outis1one/frigate_w_audio: Frigate 0.17 NVR +
  Mosquitto MQTT broker + frigate-notify → ntfy push alerts. Audio-ready
  config template with face recognition and LPR pre-configured. Prompts
  for camera credentials, media storage path (supports drive detection),
  MQTT password (auto-generated), and ntfy server. Bootstraps the
  Mosquitto passwd file. Detector choice: CPU / USB Coral / PCIe Coral.
  Hardcoded media path from upstream replaced with a configurable prompt.

https://claude.ai/code/session_01Y4dMKtkqkpvmgDKoRdzhTG

MODULAR.md

@@ -95,7 +95,7 @@ is retained as a frozen evolution record.
 | `homelab` | `caddy`, `crowdsec`, `authelia`, `homeassistant` |
 | `utilities` | `actualbudget`, `ddclient`, `filebrowser`, `fmd`, `magicmirror`, `mealie`, `meshcentral`, `ntfy`, `portainer`, `traccar`, `uptimekuma`, `watchtower`, `wg-easy` |
 | `media` | `arm`, `audiobookshelf`, `emby`, `immich`, `jellyfin`, `lyrion` |
-| `cameras` | `frigate`, `frigate-notify` |
+| `cameras` | `frigate`, `frigate-audio`, `frigate-notify`, `sky-cam` |
 | `gaming` | `js99er`, `minecraft`, `wolf`, `wolf-pair` |
 | `extras` | `linux-to-sync`, `silent-send`, `sync-cc` |
 | `backup` | `backup` |