feat(backup): take Tinyforge DB snapshot before every deploy

Adds an opt-in "auto_backup_before_deploy" setting that triggers a
"pre-deploy" backup at the start of every project deploy via the deploy
pipeline (covers both the async HTTP path and the sync poller/webhook
path). Failures are logged to the deploy log but do not abort — missing
a backup is preferable to refusing to ship a fix.

- store: settings.auto_backup_before_deploy column + scan/update wiring
- backup: accept "pre-deploy" as a valid backup_type
- deployer: small PreDeployBackuper interface, hooked into runDeploy
  right after settings load and before any state-mutating work
- api: settings request/response surface the new flag
- web: ToggleSwitch on the backup settings page; "Pre-deploy" badge
  variant in the backup list (badge-warning so it stands out)
- i18n: en/ru strings for the toggle, help text, and badge label

web/src/lib/i18n/en.json

@@ -553,6 +553,9 @@
     "restoreFailed": "Failed to restore backup",
     "typeManual": "Manual",
     "typeAuto": "Auto",
+    "typePreDeploy": "Pre-deploy",
+    "preDeploy": "Backup before every deploy",
+    "preDeployHelp": "Take a Tinyforge DB snapshot at the start of every project deploy. Independent of the periodic schedule above; restorable from this list under the \"Pre-deploy\" type.",
     "save": "Save",
     "saving": "Saving...",
     "saved": "Backup settings saved",