backups: daily backup, Back up now, download, restore.sh

A backup is data/backups/selfphoneng-YYYYMMDD-HHMM.tar.gz (mode 0600):
pg_dump, voicemail, custom sounds, music on hold, recordings if asked,
and a manifest. No generated Asterisk config: it holds plaintext
passwords and comes back from the database. The api makes one a day after
backup.time (once-a-minute check, one try a day) and the dashboard warns
when today's is missing. Settings -> Backups sets the schedule, lists them
for download and has Back up now.

scripts/restore.sh <file> refuses a backup made under another APP_SECRET
(the manifest carries a fingerprint, not the secret), asks for yes, then
replaces the database and the folders the backup has.

Tested on two throwaway servers (docker:dind running the real images):
back up on one, restore on the other. That found the api image crashing
on start since M1: tsc doesn't copy auth/common-passwords.txt into dist.
The Dockerfile copies it now and CI loads the app inside the image.

Task: M11-T3

.github/workflows/ci.yml

@@ -37,4 +37,6 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - run: docker build -f apps/api/Dockerfile -t selfphoneng-api:ci .
+      # Loads every module the way the container does: catches files tsc doesn't copy into dist.
+      - run: docker run --rm --entrypoint node selfphoneng-api:ci --input-type=module -e "await import('/app/dist/app.js')"
       - run: docker build -t selfphoneng-asterisk:ci asterisk