testing: bootstrap UI, agent reliability, NS-01..04 + alert username

Smoothes the rough edges that came up exercising a live deployment.

First-run bootstrap UI: /bootstrap renders a username + password form
that uses the in-memory token directly (operator no longer copies it
out of the log); /login redirects there while bootstrap is available.

Agent reliability: failJob synthetic envelopes so command.run early
returns no longer hang the server-side job; runtime probe of restic
restore --help drives --no-ownership instead of version sniffing
(0.18.x had it removed). Server unit re-shaped: ProtectSystem=full
plus ReadWritePaths=/etc/restic-manager, no ProtectHome — restore
can now write anywhere a user might want.

Restore wizard: default target is /root/rm-restore/<job-id>/ with
clearer help text. Re-init confirm input uses .field (was .input,
which doesn't exist — text was invisible).

NS-01 host delete: store DeleteHost, admin-band /hosts/{id}/delete
with hostname-confirm danger zone, audit, FK cascade, live WS close.

NS-02 enrollment-token recovery: outstanding-tokens panel on
/hosts/new, regenerate (preserves attachments) and revoke handlers
+ audit, store-level ListOutstandingEnrollmentTokens and
DeleteEnrollmentToken.

NS-03 repo init / probe surface: migration 0020 adds
hosts.repo_status + repo_status_error; WS handler projects every
init job's outcome onto the host row (idempotent already-initialised
collapses to ready); creds-save resets status and dispatches a fresh
probe; /hosts/{id}/repo/probe retry endpoint with banner.

NS-04 dashboard live + sort + filter: query-string filter
(q/status/repo_status/tag/sort/dir), 5s htmx live poll mirroring the
alerts pattern with a localStorage live toggle, sortable column
headers, filter row + clear.

Alerts page: ack'd-by line resolves user_id ULID to username.

Compose.yaml ignored — host-specific.

internal/restic/restore.go

@@ -87,13 +87,13 @@ func (e Env) RunRestore(ctx context.Context, snapshotID string, paths []string,
 		}
 	}
 	args = append(args, "--target", target)
-	// --no-ownership was added in restic 0.17. Older versions reject
-	// the flag with "unknown flag: --no-ownership". For new-dir
-	// restores we want the files owned by the agent user (operator
-	// can cp them without juggling chown), so pass the flag iff the
-	// running restic supports it. In-place restores always preserve
-	// ownership — that's the whole point of in-place.
-	if !inPlace && e.AtLeastVersion(0, 17) {
+	// --no-ownership is nominally a restic 0.17+ flag, but at least
+	// one downstream 0.18.1 build still rejects it. We rely on a
+	// runtime probe captured at agent startup (see
+	// SupportsRestoreNoOwnership) rather than version sniffing.
+	// In-place restores always preserve ownership — that's the whole
+	// point of in-place — so we only add the flag for new-dir mode.
+	if !inPlace && e.SupportsRestoreNoOwnership {
 		args = append(args, "--no-ownership")
 	}
 	for _, p := range paths {