feat: v0.9.2 Ask Claude on an alert starts an investigation session

- Ops Alerts → Ask Claude now calls `devdesk attach --investigate SESSION UID`.
  The server looks the alert up, writes the prompt and starts Claude in a new
  alert-<name> session with it as the first prompt, already sent. Prompts are
  stored in prompts/<session>.txt and consumed once by devdesk-claude-run.
  A session that is already running is just opened.
- The prompt has the rule, query, summary, details and labels, and where it
  runs: the CT/VM id, the node it is on now, status and HA state, and
  `ssh <node> pct exec <id> --`. It reminds Claude that HA guests move
  (`devdesk guests <id>`), and gives aggregate rules a hint.
- `devdesk guests`: Proxmox inventory over SSH (DEVDESK_PVE_NODES). pvesh
  gives the cluster view; each node gives lxc-info and guest-agent IPs.
  Cached in guests.json, keeping last-seen IPs for stopped guests; --alerts
  refreshes it in the background every 5 minutes.
- Alerts carry uid, query, description and targets, matched by instance
  IP/host or by name; each card shows the target.
- cmd_alerts moves to libexec/devdesk-ops.sh.

Closes #39

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

web/styles.css

@@ -402,6 +402,9 @@ body.dd-sidebar-open .dd-sidebar {
 .dd-alert-name { font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .dd-alert-age { margin-left: auto; white-space: nowrap; }
 .dd-alert-instances { overflow-wrap: anywhere; }
+.dd-alert-where { color: var(--accent-cyan); font-family: var(--font-mono); overflow-wrap: anywhere; }
+.dd-alert-where::before { content: "\2192  "; color: var(--text-muted); }
+.dd-alert-where.is-guess { color: var(--text-secondary); }
 .dd-alert-summary { color: var(--text-secondary); }
 .dd-alert .dd-ask { align-self: flex-start; margin-top: 2px; }
 .dd-all-clear { display: flex; align-items: center; gap: var(--space-sm); color: var(--accent-green); font-size: 0.74rem; }