feat(hosts): the Hosts list labels its figures and says how long; SLA tab gone; one place to add a host (#5279–#5283)

Hosts list:
- CPU and Memory are their own labelled columns (#5279); a silent
  agent's last readings are greyed, and Status says "agent silent for 7m".
- One uptime figure, 30 days, with 24h and 7d on hover. The SLA tab
  (/hosts/uptime) repeated it and is removed (#5280; one home per fact).
- Status is a word with how long ("Down for 12m"); host_status now carries
  down_since. Edit and Delete live on the host's page only (#5281).
- Figures are right-aligned with tabular digits (.table .num), not a
  monospace face.

Agent fleet (#5282): its add-host form is gone, so hosts are added only on
Hosts -> Add host. That form was also the only way to get a token for a
manual curl install, so that moves to the host's Agent card as "Install
manually" (POST /fleet/<host_id>/register), shown on the fleet page as
before. "Delete" there reads "Unregister".

Add host (#5283): laid out like the add-monitor form; a name clash comes
back inline with what was typed instead of a bare text 400; the address
is optional, as the host page already allowed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugins/host_agent/routes.py

@@ -796,35 +796,24 @@ async def fleet():
     )
 
 
-@host_agent_bp.post("/fleet/add-host")
+@host_agent_bp.post("/fleet/<host_id>/register")
 @require_role(UserRole.admin)
-async def add_host():
-    form = await request.form
-    name = (form.get("name") or "").strip()
-    address = (form.get("address") or "").strip()
-    if not name:
-        return _error(400, "missing_name")
-
+async def register_host(host_id: str):
+    """Issue an agent token for an existing host, for a manual install: the
+    fleet page then shows the one-line install command, once. Hosts are added
+    on Hosts → Add host; this is only the agent half (#5282)."""
     async with current_app.db_sessionmaker() as session:
-        host = (await session.execute(
-            select(Host).where(Host.name == name))).scalar_one_or_none()
+        host = await session.get(Host, host_id)
         if host is None:
-            host = Host(name=name, address=address)
-            session.add(host)
-            await session.flush()
+            return _error(404, "not_found")
         existing = (await session.execute(
             select(HostAgentRegistration).where(
                 HostAgentRegistration.host_id == host.id))).scalar_one_or_none()
         if existing is not None:
-            await session.rollback()
             return _error(400, "already_registered")
-
         raw, hashed = _new_token_pair()
-        reg = HostAgentRegistration(host_id=host.id, token_hash=hashed)
-        session.add(reg)
+        session.add(HostAgentRegistration(host_id=host.id, token_hash=hashed))
         await session.commit()
-        host_id = host.id
-
     return redirect(url_for("host_agent.fleet") + f"?new_token={raw}&host_id={host_id}")
 
 

plugins/host_agent/templates/panel.html

@@ -91,8 +91,7 @@
 
   {% elif not ansible_available %}
   <p style="color:var(--text-dim);font-size:0.85rem;">
-    Ansible isn't available, so the agent can't be deployed from here. Install it manually with the
-    <a href="/plugins/host_agent/fleet/">curl install command</a>.
+    Ansible isn't available, so the agent can't be deployed from here. Install it manually instead (below).
   </p>
 
   {% elif not managed_key_set %}
@@ -141,6 +140,16 @@
   </form>
   {% endif %}
 
+  {% if not reg and session.user_role == 'admin' %}
+  {# A manual install: no Ansible, no SSH. Issues this host's token and shows
+     the one-line install command on the fleet page, once (#5282). #}
+  <form method="post" action="/plugins/host_agent/fleet/{{ host.id }}/register"
+        style="display:flex;gap:0.6rem;align-items:center;flex-wrap:wrap;margin:0.75rem 0 0;">{{ csrf_field() }}
+    <span style="font-size:0.78rem;color:var(--text-muted);">Or by hand on the host:</span>
+    <button type="submit" class="btn btn-sm btn-ghost">Install manually</button>
+  </form>
+  {% endif %}
+
   {% if reg and session.user_role == 'admin' %}
   <form method="post" action="/plugins/host_agent/fleet/{{ host.id }}/delete" style="margin:0.75rem 0 0;"
         data-confirm="Clear this pending registration? Its token is discarded.">{{ csrf_field() }}

plugins/host_agent/templates/settings_list.html

@@ -8,7 +8,8 @@
 </div>
 <p style="color:var(--text-muted);font-size:0.84rem;margin:-0.4rem 0 1.25rem;">
   Bulk agent operations across your inventory. For a single host, use its
-  <a href="/hosts/">host page</a> — provisioning and metrics live there.
+  <a href="/hosts/">host page</a>: provisioning, a manual install command and
+  metrics live there. New hosts are added with <a href="/hosts/new">Add host</a>.
 </p>
 
 {% if new_token %}
@@ -47,34 +48,19 @@
           </form>
           <form method="post" action="/plugins/host_agent/fleet/{{ item.reg.host_id }}/delete"
                 style="display:inline;"
-                data-confirm="Delete the agent registration for {{ item.name }}? The agent will be unable to report metrics until re-registered.">{{ csrf_field() }}
-            <button type="submit" class="btn btn-danger btn-sm">Delete</button>
+                data-confirm="Unregister the agent for {{ item.name }}? Its token stops working and metrics stop until it is registered again. The agent itself stays installed on the host.">{{ csrf_field() }}
+            <button type="submit" class="btn btn-danger btn-sm">Unregister</button>
           </form>
         </td>
       </tr>
       {% else %}
-      <tr><td colspan="7" class="empty">No hosts registered. Add one below.</td></tr>
+      <tr><td colspan="7" class="empty">No agents registered yet. <a href="/hosts/new">Add a host</a>, then install its agent from the host's page.</td></tr>
       {% endfor %}
     </tbody>
   </table>
   </div>
 </div>
 
-<div class="card">
-  <form method="post" action="/plugins/host_agent/fleet/add-host"
-        style="display:flex;gap:0.75rem;align-items:flex-end;flex-wrap:wrap;">{{ csrf_field() }}
-    <div class="form-group" style="margin-bottom:0;">
-      <label>Host name</label>
-      <input type="text" name="name" required>
-    </div>
-    <div class="form-group" style="margin-bottom:0;">
-      <label>Address (optional)</label>
-      <input type="text" name="address">
-    </div>
-    <button type="submit" class="btn">Add host</button>
-  </form>
-</div>
-
 {% if ansible_available %}
 {% set scope_select %}
         <label>Target</label>