Local backup: daily scheduled + before destroy

[titouanmathis]

Summary

Closes #1 (partial — local backup only, remote storage to come later).

Adds local backup support to trafic with two triggers:

• Daily scheduled backups via the agent (configurable hour, retention)
• Automatic backup before destroy in the CLI

Agent changes (packages/trafic-agent/)

New types

• BackupConfig — configuration for [backup] TOML section
• BackupResult / BackupEntry — result and listing types

Config (src/utils/config.ts)

• Parse [backup] section with defaults: disabled, 3am schedule, 7-day retention, /var/backups/trafic

Core logic (src/tasks/backup.ts)

• backupProjectDb() — exports a project DB via ddev export-db --gzip
• backupAgentData() — copies agent SQLite DB and config file
• runBackup() — backup all or a specific project
• listBackups() — list available backups grouped by date
• cleanOldBackups() — remove backups older than retention period
• restoreProjectDb() — restore via ddev import-db
• findBackup() — find latest or date-specific backup file

Auto-starts stopped projects before export/import. Backups stored as <localDir>/<YYYY-MM-DD>/<project>.sql.gz.

Scheduler (src/tasks/backup-scheduler.ts)

• Simple daily scheduler: checks every 30min, runs once per day after the configured hour
• Runs cleanup after each backup

CLI commands (src/cli.ts)

• trafic-agent backup — backup all projects
• trafic-agent backup --name my-app — backup a specific project
• trafic-agent backup --list — list available backups
• trafic-agent backup --clean — clean old backups
• trafic-agent restore --name my-app — restore from latest backup
• trafic-agent restore --name my-app --date 2026-02-07 — restore from specific date

CLI changes (packages/trafic-cli/)

Backup before destroy (src/commands/destroy.ts)

• Runs trafic-agent backup --name <project> via SSH before ddev delete
• Non-blocking: warns and continues if backup fails
• Skip with --no-backup flag

Tests

• 13 new tests for backup logic (listBackups, cleanOldBackups, findBackup)
• Updated destroy tests for the new backup step (+2 new tests for --no-backup and backup failure)
• All 92 tests pass (62 agent + 30 CLI)

Config example

[backup]
enabled = true
schedule_hour = 3
retain_days = 7
local_dir = "/var/backups/trafic"

Future work

• Remote storage (S3, rsync, rclone) — separate PR
• Uploads backup (tar project upload dirs) — separate PR