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/routes/settings/backup/+page.svelte

@@ -19,6 +19,7 @@
 	let backupEnabled = $state(false);
 	let backupIntervalHours = $state('24');
 	let backupRetentionCount = $state('10');
+	let autoBackupBeforeDeploy = $state(false);
 	let backups = $state<BackupInfo[]>([]);
 
 	let confirmDeleteId = $state('');
@@ -38,6 +39,7 @@
 			backupEnabled = settings.backup_enabled ?? false;
 			backupIntervalHours = String(settings.backup_interval_hours ?? 24);
 			backupRetentionCount = String(settings.backup_retention_count ?? 10);
+			autoBackupBeforeDeploy = settings.auto_backup_before_deploy ?? false;
 			backups = backupList ?? [];
 		} catch (err) {
 			toasts.error(err instanceof Error ? err.message : 'Failed to load backup settings');
@@ -53,7 +55,8 @@
 			await updateSettings({
 				backup_enabled: backupEnabled,
 				backup_interval_hours: Math.max(1, parseInt(backupIntervalHours, 10) || 24),
-				backup_retention_count: Math.max(1, parseInt(backupRetentionCount, 10) || 10)
+				backup_retention_count: Math.max(1, parseInt(backupRetentionCount, 10) || 10),
+				auto_backup_before_deploy: autoBackupBeforeDeploy
 			});
 			toasts.success($t('settingsBackup.saved'));
 		} catch (err) {
@@ -181,6 +184,15 @@
 					</div>
 				{/if}
 
+				<!-- Pre-deploy backup toggle: independent of the periodic auto-backup. -->
+				<div class="flex items-center gap-3">
+					<ToggleSwitch bind:checked={autoBackupBeforeDeploy} label={$t('settingsBackup.preDeploy')} />
+					<div>
+						<span class="text-sm font-medium text-[var(--text-primary)]">{$t('settingsBackup.preDeploy')}</span>
+						<p class="text-xs text-[var(--text-tertiary)]">{$t('settingsBackup.preDeployHelp')}</p>
+					</div>
+				</div>
+
 				<div class="flex items-center gap-3">
 					<button onclick={handleSave} disabled={saving}
 						class="inline-flex items-center gap-2 rounded-lg bg-[var(--color-brand-600)] px-4 py-2.5 text-sm font-medium text-white shadow-sm transition-all duration-150 hover:bg-[var(--color-brand-700)] disabled:opacity-50 active:animate-press">
@@ -233,8 +245,12 @@
 									<td class="px-4 py-3 text-[var(--text-secondary)]">{formatSize(backup.size_bytes)}</td>
 									<td class="px-4 py-3">
 										<span class="inline-flex items-center rounded-full px-2 py-0.5 text-xs font-medium
-											{backup.backup_type === 'auto' ? 'badge-info' : 'badge-success'}">
-											{backup.backup_type === 'auto' ? $t('settingsBackup.typeAuto') : $t('settingsBackup.typeManual')}
+											{backup.backup_type === 'auto' ? 'badge-info' : backup.backup_type === 'pre-deploy' ? 'badge-warning' : 'badge-success'}">
+											{backup.backup_type === 'auto'
+												? $t('settingsBackup.typeAuto')
+												: backup.backup_type === 'pre-deploy'
+													? $t('settingsBackup.typePreDeploy')
+													: $t('settingsBackup.typeManual')}
 										</span>
 									</td>
 									<td class="px-4 py-3 text-[var(--text-secondary)]">{$fmt.dateTime(toUtcIso(backup.created_at))}</td>