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.

web/templates/pages/host_detail.html

@@ -110,10 +110,21 @@
       <div class="panel rounded-[7px] px-4 py-3.5">
         <div class="text-[11px] text-bad uppercase tracking-[0.1em] font-semibold mb-2.5">Danger zone</div>
         <p class="text-pretty text-[12px] text-ink-mute leading-[1.55] mb-3">
-          Removes the host record. The repo data on the rest-server is left intact —
-          you delete that yourself.
+          Removes the host record and everything attached to it
+          (schedules, source groups, jobs, snapshots metadata, alerts).
+          The agent's bearer is revoked, so a re-installed instance
+          comes back through the normal pending-host accept flow.
+          The repo data on the rest-server is left intact — you delete
+          that yourself.
         </p>
-        <button class="btn btn-danger w-full justify-center" disabled title="lands later in Phase 1">Remove host…</button>
+        <form method="post" action="/hosts/{{$host.ID}}/delete"
+              class="space-y-2"
+              onsubmit="return confirm('Remove host &quot;{{$host.Name}}&quot;? This cascades to every dependent row and cannot be undone.');">
+          <input type="text" name="confirm_hostname" required autocomplete="off"
+                 placeholder="type hostname to confirm"
+                 class="field mono text-[12px]" />
+          <button type="submit" class="btn btn-danger w-full justify-center">Remove host…</button>
+        </form>
       </div>
 
     </aside>