Add sky-cam-frigate service using Frigate exports for timelapse source

Duplicates services/sky-cam.sh into a Frigate-backed variant that pulls
recordings via Frigate's export API instead of a JPEG image folder.
Includes a frigate-retime.sh helper that exports a coarse timelapse,
measures its actual duration with ffprobe, and re-encodes once with a
computed setpts factor to hit an exact target length (e.g. a Four
Seasons movement's runtime).

README.md

@@ -69,7 +69,7 @@ Update them any time with `sudo ./setup.sh configure`.
 | `homelab` | `caddy`, `crowdsec`, `authelia`, `homeassistant`, `asterisk`, `sunshine` |
 | `utilities` | `actualbudget`, `ai-gpu`, `ai-stack`, `archivebox`, `changedetection`, `ddclient`, `filebrowser`, `fmd`, `gatus`, `homebox`, `iopaint`, `joplin`, `koha`, `magicmirror`, `mail-archiver`, `mattermost`, `mealie`, `meshcentral`, `n8n`, `nextcloud`, `ntfy`, `onlyoffice`, `paintplus`, `portainer`, `rustdesk`, `stirling-pdf`, `syncthing`, `traccar`, `unifi`, `uptimekuma`, `vaultwarden`, `watchyourlan`, `watchtower`, `wg-easy` |
 | `media` | `arm`, `audiobookshelf`, `calibre-web`, `emby`, `immich`, `jellyfin`, `lyrion` |
-| `cameras` | `frigate`, `frigate-audio`, `frigate-notify`, `sky-cam` |
+| `cameras` | `frigate`, `frigate-audio`, `frigate-notify`, `sky-cam`, `sky-cam-frigate` |
 | `gaming` | `drum-rhythm-game`, `js99er`, `kyber-launcher`, `kyber-server`, `minecraft`, `wolf`, `wolf-pair` |
 | `extras` | `kdeconnect`, `silent-send`, `sync-cc` |
 | `backup` | `backup` — complete recovery: entire `~/docker/<service>/` for every service via Kopia (Minecraft: flush+snap, no downtime; others: stop/snap/start for DB consistency); `borg-backup` — same coverage via Borg (chunk dedup, SSH remote repos, Borgmatic/Vorta compatible); `gaming-backup` — frequent game-save snapshots (Minecraft world data, emulator saves, Steam — no downtime, run hourly) |
@@ -142,6 +142,7 @@ cameras
   frigate-audio
   frigate-notify
   sky-cam
+  sky-cam-frigate
 
 gaming
   drum-rhythm-game